Dariusz Bochenek - Academia.edu (original) (raw)

Papers by Dariusz Bochenek

Research paper thumbnail of Electrophysical Properties of PZT-Type Ceramics Obtained by Two Sintering Methods

Applied Sciences

This study demonstrates the impact of two sintering techniques on the fundamental properties of d... more This study demonstrates the impact of two sintering techniques on the fundamental properties of doped PZT-type ceramic materials (with Mn4+, Sb3+, Gd3+, and W6+), with the general chemical formula Pb(Zr0.49Ti0.51)0.94Mn0.021Sb0.016Gd0.012W0.012O3. The synthesis of ceramic powders was carried out through the calcination method. Two different methods were used in the final sintering process: (i) pressureless sintering (PS) and (ii) hot pressing (HP). The PZT-type ceramics were subjected to electrophysical measurements, encompassing various analyses such as X-ray diffraction (XRD), microstructure (scanning electron microscopy (SEM)), ferroelectric and dielectric properties, and DC electrical conductivity. The analysis of the crystal structure at room temperature showed that the material belongs to the perovskite structure from the tetragonal phase (P4mm space group) without foreign phases. Both sintering methods ensure obtaining the material with appropriate dielectric and ferroelectri...

Research paper thumbnail of Magnetoelectric Composites: Engineering for Tunable Filters and Energy Harvesting Applications

Applied Sciences

Multiferroic ceramic composites have been engineered to incorporate multiple desired physical pro... more Multiferroic ceramic composites have been engineered to incorporate multiple desired physical properties within a single ceramic component. The objective of this study was to create such composites through pressure less sintering ferroelectric-doped PZT and nickel–zinc ferrite at a temperature of 1250 °C. The growth of ferrite grains was found to be influenced by the concentration of the ferroelectric PZT phase. Consequently, an increase in the ferrite content decreased the average particle size of nickel–zinc ferrite by a factor of 1.8. After impedance spectroscopy, the multiferroic ceramic composites can be categorized into two groups: those with low ferrite content (<20%) and those with a high ferrite content (>20%). Composites with a high ferrite content are suitable for dual-band filters or shield applications. The impedance spectroscopy analysis revealed that the resonance frequency can be shifted to higher frequency ranges. Therefore, it was demonstrated that modifying ...

Research paper thumbnail of The Magnetic and Electric Measurements of the Multiferroic PbFe1/2Nb1/2O3 Ceramics Obtained Using Hot Uniaxial Pressure Method

Archives of Metallurgy and Materials

We present the results of investigations of Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ceramic samples obtained u... more We present the results of investigations of Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ceramic samples obtained using two-step synthesis (i.e. columbite method). For obtained samples complex investigations of microstructure, magnetic and electrophysical properties have been performed at low and at high temperatures. Microstructure is characterized by small grains with high homogeneity and high density (low porosity). Impedance of samples and the phase shift angle have been measured using LCR Meter. Next the AC electric conductivity, dielectric permittivity and loss tangent have been calculated. AC conductivity at frequency 3 Hz was measured in similar way using Quantum Design PPMS System in magnetic fields 1000 Oe and 10000 Oe. At temperature range 240K-260K the anomalies of conductivity are observed. These anomalies depend on measuring cycle (heating, cooling) and magnetic field.

Research paper thumbnail of Obtaining and Main Dielectric Properties of Ba0.6Pb0.4TiO3/graphene Oxide Composite

In this paper there is described the technology of obtaining and results of investigations of mic... more In this paper there is described the technology of obtaining and results of investigations of microstructure, XRD, SEM, main dielectric properties, electrical conductivity measurements and P-E hysteresis loops of Ba0.6Pb0.4TiO3/graphene oxide composite (abbr. BPT/GO). In the final step of technology, the samples have been sintered using the Spark Plasma Sintering (SPS) method. Diffraction patterns of BPT/GO composite exhibit lines which can be related with perovskite structure, as well as reveal additional lines that can be derived from the initial component oxides. Investigations of electrical conductivity suggest that the PTCR effect occurs at temperatures up to about 120°C. Dielectric hysteresis loops below 90°C are wide and typical for materials with rather high electrical conductivity. The hysteresis loop obtained at 120°C is more typical for ferroelectrics. The obtained material is interesting, however it is probably possible to find better conditions of obtaining it and/or a ...

Research paper thumbnail of Basic properties of the PFN ceramic doped by potassium

Research paper thumbnail of Podstawowe właściwości ceramiki PFN domieszkowanej potasem

In the work, PFN ceramics were obtained by a one-step synthesis. The ceramics were modio ed with ... more In the work, PFN ceramics were obtained by a one-step synthesis. The ceramics were modio ed with the help of potassium incorporated in an amount of 1.0%, 2.0%, 3.0%, 4.0% and 6.0 mol%. Effects of the potassium dopant on the crystal structure, microstructure and main properties of the PFN ceramics were studied. It has been shown that the heterovalence doping of PFN by the potassium in the amount of 2.0-4.0 mol%. had a positive effect on the density and microstructural homogeneity of the ceramic samples. Such a potassium admixture limited the formation of the non-ferroelectric (pirochlore) phase during the technological process. Measurements of dielectric properties of the doped compositions have shown that potassium causes a decrease of the maximum permittivity and reduces slightly the degree of blur of the phase transition. There is also an increase in the dielectric loss and electrical conductivity. There was no a clear trend in the effect of the incorporated potassium additive on ...

Research paper thumbnail of Wpływ koncentracji PbTiO3 na podstawowe parametry piezoelektryczne nanoceramiki PZT

Research paper thumbnail of Struktura i właściwości fizyczne ceramiki 46/54 PZT modyfikowanej strontem, chromem i neodymem

Research paper thumbnail of Multi-component PZT ceramics obtained by mechanochemical activation and conventional ceramic technology

Journal of Thermal Analysis and Calorimetry, 2019

In the paper, the multi-component PZT-type ceramics doped with Mn 4+ , Sb 3+ , W 6+ and Ni 2+ wer... more In the paper, the multi-component PZT-type ceramics doped with Mn 4+ , Sb 3+ , W 6+ and Ni 2+ were investigated. The following chemical composition was selected: Pb(Zr 0.49 Ti 0.51) 0.94 Mn 0.01 Sb 0.03 W 0.015 Ni 0.01 O 3. The ceramic powders were synthesized by two methods: (i) the classical technological method using powder calcination and (ii) mechanochemical synthesis at room temperature. Densification of the powders (sintering) was carried by free sintering method. In the case of the mechanochemical activation, the development of the synthesis has been monitored by XRD and SEM investigations after different milling periods (25 h, 50 h and 75 h). From the obtained powder, the bulk ceramic samples have been prepared by uniaxial pressing and subsequent sintering. The ceramic multi-component PZT-type samples were characterized in wide temperature range by DTA, TG, DC electrical conductivity, XRD, SEM and EDS (energy-dispersive spectrometry) methods, and their ferroelectric, dielectric and piezoelectric properties were studied. At the work, a comparison of test results for samples obtained by two methods was made. The X-ray investigations confirmed that the obtained material exhibits a perovskite-like structure with a tetragonal phase (close to the morphotropic area). The detailed results of the multi-component PZT-type ceramics predispose these materials in microelectronic applications, for example, as element of the actuators and piezoelectric transducers. The application of the mechanochemical synthesis to obtain the PZT-type materials allows to shorten the time of the technological process, and at the same time not to reduce the electrophysical properties of ceramic samples.

Research paper thumbnail of High-density lead-free K0.5Bi0.5TiO3 ceramics: preparation, mechanical and dielectric properties

Phase Transitions, 2018

The preparation of high-density lead-free potassium-bismuth titanate K 0.5 Bi 0.5 TiO 3 about 96-... more The preparation of high-density lead-free potassium-bismuth titanate K 0.5 Bi 0.5 TiO 3 about 96-98% of the calculated density (X-ray), confirmed by the Archimedes method, is presented. All stages of the technological process are explained in detail. The control of microstructure was performed by scanning electron microscopy. The crystal structure and phase content of samples were determined by X-ray diffraction at each stage of sintering. Four types of samples were obtained under various technological conditions. The ultrasonic measurements of the obtained samples were carried out and basic parameters were determined, such as Young and Kirchoff modulus and Poisson's ratio were determined at room temperature. The dielectric measurements show that the maximum value of dielectric permittivity is shifted towards higher temperatures as the frequency increases. This feature is characteristic of ferroelectric relaxor materials. The presented materials can be a good starting point for the development of lead-free ceramics.

Research paper thumbnail of Magnetoelectric and electric measurements of the (1− x )BiFeO 3 –( x )Pb(Fe 1/2 Nb 1/2 )O 3 solid solutions

Materials Chemistry and Physics, 2017

Highlights  BF-PFN samples have a densely packed microstructure, with well crystallized grains. ... more Highlights  BF-PFN samples have a densely packed microstructure, with well crystallized grains.  Bi atoms possibly migrate from BF toward PFN component during sintering.  BF-PFN have a diffuse character of the ferroelectric-paraelectric phase transition.  Magnetoelectric coefficient ( ME) for BF-PFN is higher, than for pure BF.  The  ME for BF-PFN is about three times higher than for 0.75BiFeO 3-0.25BaTiO 3 .

Research paper thumbnail of The Positive Temperature Coefficient of Resistivity Effect in the Pb(Fe1/2Nb1/2)O3Ceramics Admixed with Lithium

Acta Physica Polonica A, 2009

In the paper technological conditions were looked for to obtain the Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ce... more In the paper technological conditions were looked for to obtain the Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ceramics and the PFN ceramics with the lithium admixture with the highest electric conduction and conditions appropriate for the PTC-R effect formation. Measurements of dc electrical resistivity, dielectric permittivity and dielectric loss were made as functions of temperature from room temperature to 190 • C, at 1 kHz. The best set of values of dielectric loss and dielectric constant, from the ferroelectricity point of view, were obtained when the precursor with orthorhombic structure was employed. By creating appropriate technological conditions in the PFN ceramics the PTC-R effect can occur above the Curie temperature. Their electric properties are determined by presence of a basic phase of the potential barrier on the grain boundaries.

Research paper thumbnail of Technology and Main Properties of PMN-PT-Ferrite Multiferroic Ceramic Composite Materials

7th Forum on New Materials - Part B, 2016

In the presented work composite ferroelectric/ferrimagnetic ceramics have been obtained and descr... more In the presented work composite ferroelectric/ferrimagnetic ceramics have been obtained and described. The investigated material is based on PMN-PT powders and Ni-Zn ferrite powder. The Powders of ferroelectric component (i.e. (1–x)PMN-(x)PT with x from 0.25 to 0.40 with step 0.03 were synthesized using the sol-gel method. The magnetic component i.e. nickel-zinc ferrite was obtained from oxides using the classic method of obtaining ceramics. The compositions of PMN–PT used by us have rhombohedral or tetragonal symmetries, or belong to morphotropic region. The final ceramic composite samples were obtained using the classic method of ceramic technology with calcination route and final pressureless densification using free sintering. In this paper, XRD, EDS dielectric and magnetic properties have been investigated and described for the obtained composite ceramic samples.

Research paper thumbnail of The Basic Properties of the Ferroelectromagnetic Composites Based on the Ferrite and PZT-Type Powders

Advances in Science and Technology, 2016

In this paper a ferroelectric–ferromagnetic composites based on a doped PZT-type and ferrite powd... more In this paper a ferroelectric–ferromagnetic composites based on a doped PZT-type and ferrite powders were presented. Ferroelectric powder (in amount of 85.0 wt-%) was based on multicomponent PZT-type materials: i) Pb(Zr0.51Ti0.49)O3+0.2%at.Bi2O3+0.03%at.Nb2O5+ 0.06%at.MnO2, ii) Pb0.84Ba0.16(Zr0.54Ti0.46)O3+1.0%at.Nb2O5, while nickel–zinc ferrite Ni0.64Zn0.36Fe2O4 (in amount of 15.0 wt-%) served as the magnetic component of the composite samples. The synthesis of the ferroelectric–ferromagnetic composite’s powders was performed by solid state method, while final densification of the synthesized powders was achieved using free sintering method.Conducted basic tests indicate that obtained ferroelectromagnetic ceramic composites (PZT-ferrite type) exhibit good properties giving the possibility to use them to construct magnetoelectric transducers.

Research paper thumbnail of Dielectric properties of the PZT ceramics obtained by the sol-gel method and doped by chromim, manganium and tantalum

Materialy Ceramiczne Ceramic Materials, 2014

In this paper we obtained multicomponent PZT ceramics doped by chromium, manganese and tantalum o... more In this paper we obtained multicomponent PZT ceramics doped by chromium, manganese and tantalum oxides. Ceramic powder with a composition of Pb(Zr0,70Ti0,30)O3 was synthesized by the sol-gel method. In the next step, the powder was doped by an oxide: Cr2O3, MnO2 or Ta2O5. Two compositions of ceramic powders were obtained with constant amounts of manganese (1.0%) and chromium (0.15%) oxides, but with different percentages of tantalum oxide (0.03% and 0.05%). Synthesis of the materials was carried out by solid phase reaction, using calcination of powder compacts compacting method, while the sintering was performed by two methods: free sintering (FS) - with no pressure, and hot pressing (HP). For the obtained ceramic samples, microstructural, X-ray, EDS, basic dielectric property and electrical hysteresis loop investigations were carried out. The studies have shown that the use of the hot pressing method allows obtaining the materials with higher values of maximum electric permittivity, but with higher values of dielectric losses, when compared with the FS obtained ones. The doping of the basic PZT composition by tantalum, manganese and chromium oxides decreases the temperature of phase transition (Tm) and increases the ferroelectric hardness. The properties of multicomponent free sintered PZT ceramics permit its

Research paper thumbnail of Ferroelectromagnetic solid solutions on the base piezoelectric ceramic materials for components of micromechatronics

Mechanical Systems and Signal Processing, 2016

Abstract In the presented work, a ferroelectromagnetic solid solutions based on PZT and ferrite p... more Abstract In the presented work, a ferroelectromagnetic solid solutions based on PZT and ferrite powders have been obtained. The main aim of combination of ferroelectric and magnetic powders was to obtain material showing both electric and magnetic properties. Ferroelectric ceramic powder (in amount of 90%) was based on the doped PZT type solid solution while magnetic component was nickel–zinc ferrite Ni 1− x Zn x Fe 2 O 4 (in amount of 10%). The synthesis of components of ferroelectromagnetic solid solutions was performed using the solid phase sintering. Final densification of synthesized powder has been done using free sintering. The aim of the work was to obtain and examine in the first multicomponent PZT type ceramics admixed with chromium with the following chemical composition Pb 0.94 Sr 0.06 (Zr 0.46 Ti 0.54 )O 3 +0.25 at% Cr 2 O 3 and next ferroelectromagnetic solid solution based on a PZT type ferroelectric powder (Pb 0.94 Sr 0.06 (Zr 0.46 Ti 0.54 )O 3 +0.25 at% Cr 2 O 3 ) and nickel–zinc ferrite (Ni 0.64 Zn 0.36 Fe 2 O 4 ), from the point of view of their mechanical and electric properties, such as: electric permittivity, e ; dielectric loss, tanδ ; mechanical losses, Q −1 ; and Young modulus, E .

Research paper thumbnail of Influence of the Technology Conditions on the Mechanical and Dielectric Properties of the PZT-Base Piezoceramic Transducers

Solid State Phenomena, 2003

Application of the piezoceramics produced on the base of the PZT-type s olid solution in modern e... more Application of the piezoceramics produced on the base of the PZT-type s olid solution in modern electroacoustics depends primary on its mechanical and electr ica pa ameters. Multicomponent ceramic materials of the PZT-type are characterized by the occurrence of the morphotrophy area, it means the area of the rhombohedral and tetragonal phase coexistence. T he position and width of the area depends on the solid chemical solution and the technology used for obtai ning it. Therefore, selecting the suitable methods and conditions for producing piezoceramics is very impo tant since it has a direct influence on its properties. This work presents results of the investigations of the piezocerami c samples of the PZT-type received by the hot pressing method and the conventional sintering in different condi ions. The results obtained will be used to optimize the technological process and will indicate possibilities of wider applications of PZT-type piezoceramics in modern technology. Introduction Apart from the chemical composition and microstructure of ferroelec tric eramics temporary and temperature stability of their mechanical and dielectric param eters constitute important factors influencing their range of application. This has been confirmed by invest gations of the multicomponent solid state solutions of the PZT-type, conducted by differ ent methods [1 6]. Mechanical spectroscopy due to its high sensitivity to changes taking place in the real structure of materials has been more often used in recent investigations [6]. To observe changes occurring in the domain structure and to determine the stability of mechanical and die lectric parameters, the application of mechanical spectroscopy and the resonance-anti-resonance method is used. The influence of the conditions of the technological process on the stabil ity of temperature, on the mechanical properties and on the basic dielectric parameters of t he multicomponent piezoelectric ceramics of the PZT-type is shown. These investigations were ai m d at controlling the manufacturing process of ceramics to be used in ultrasound generators of high power e ngines and in piezoelectric transformers. Experimental The material used in this study was the ceramics belonging to te rnary solid solutions of the PZT-type with the following chemical composition: Pb (Zr 0.51 Ti0.49) O3 + Pb (Nb0.5 Mn0.5) O3 + 2.15 wt % Bi 2O3; its dielectric parameters show that it belongs to ceramics of medium ferroe lect ic hardness. The ceramics was obtained in different technological conditions by the hot pressing method in nitrogen or in argon atmosphere, and by the classical sintering method. A synthesized powder of the Solid State Phenomena Online: 2003-02-13 ISSN: 1662-9779, Vol. 89, pp 303-308 doi:10.4028/www.scientific.net/SSP.89.303 © 2003 Trans Tech Publications Ltd, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (Semanticscholar.org-18/03/20,14:08:25) ceramics was used to manufacture the investigated ceramics. In the hot pressing technology 25 MPa pressure was used and moulded pieces were sintered for 1h at 1473 K. In the classical sintering method the sintering temperature was 1523 K while the sintering time was 2 h. After completing the technological process all specimens were ground and polished. Electrodes on all specimens were formed by the silver paste burning method. The obtained samples were subjected to polarization using the low te mperature method at 432 K for 30 min; the intensity of the polarization field was E p = 35 kV/cm. After completing the polarization process measurements of dielectric values in the temperature depe ndenc function were performed by an automatic capacity bridge of a Tesla BM 595 type at the meas urement field frequency of 1 kHz. Stability tests of dielectric parameters were carried out in the temper atur range from 273 K to 423 K. Measurements of mechanical properties performed by a rezonant mecha nical spectrometer of the RAK-2 type, enabled us to measure the temperature dependences of the i nternal friction and of the dynamic Young’s modulus [7]. Young’s modulus, the transverse elasticity m odulus, and Poisson’s’ coefficient (ν) were determined by the UMT-11 ultrasonic flaw detector [8]. The phase analysis of the investigated ceramics was carried out in an X-ray diffractome er (H2G-4B type). It was found that at room temperature the ceramics had a tetragonal structure with t he following lattice constants: a o = 4.076 Å, co = 4.114 Å, and an elementary cell deformation parameter sigma δT = 0.9 %. Results and Discussion Figure 1 presents selected examples of temperature dependence of t he electric permittivity ε and the dielectric loss tg δ for the ceramics formed in different technological conditions. It c an be seen that the ceramics obtained by the classical method exhibits a phase…

Research paper thumbnail of Nano-indentation studies and macro-scale mechanical testing of vanadium modified BBN ceramics

World Journal of Engineering, 2012

The mechanical properties of the pure as well as vanadium modified BaBi2Nb2O9 ceramics have been ... more The mechanical properties of the pure as well as vanadium modified BaBi2Nb2O9 ceramics have been studied in macro and nano-scales using three different methods. Specifically for macro-scale, ultrasonic velocity and internal friction were employed to evaluate the Young modulus (E), whereas for nano-scale the nanoindentation method was a very useful tool to obtain the elastic modulus and hardness. These results reveal the strong influence of vanadium admixture on mechanical properties of the discussed material. In the case of modified ceramics the value of Young modulus increases, which is probably connected with the decreasing of the number of defects. Moreover, the described results show the significant differences in mechanical properties measured on nano and macro-scale. It is concluded that the knowledge of the mechanical properties of the ceramic material is complete only when we take into account both the macro and nano-scale.

Research paper thumbnail of Ferroelectric and magnetic properties of ferroelectromagnetic PbFe1/2Nb1/2O3 type ceramics

Journal of Magnetism and Magnetic Materials, 2011

PbFe 1/2 Nb 1/2 O 3 (PFN) ceramics, to which an admixture of manganese oxide (MnO 2) was added, w... more PbFe 1/2 Nb 1/2 O 3 (PFN) ceramics, to which an admixture of manganese oxide (MnO 2) was added, was obtained by calcination of the powder in a single stage synthesis. Compacting was made by a free sintering method. Results of investigations of microstructure, magnetic, magnetoelectric, dielectric and piezoelectric properties and electric conductivity vs. temperature are presented. The influence of manganese admixture on the physical properties of the PFN ceramics is presented. The admixtures decrease the electric conduction of the PFN ceramic specimens.

Research paper thumbnail of Magnetic and ferroelectric properties of PbFe1/2Nb1/2O3 synthesized by a solution precipitation method

Journal of Alloys and Compounds, 2010

Results of an influence of the technological conditions on ferroelectric and magnetic properties ... more Results of an influence of the technological conditions on ferroelectric and magnetic properties of the PbFe 1/2 Nb 1/2 O 3 ceramics (PFN) are presented. Synthesizing of the PFN material was made by a chemical solution precipitation method and sintering (compacting) by a free sintering method. Temperatures of dehydratization, burning of an organic phase and crystallization of an amorphous powder were determined by the thermal analysis (TA) method. The structure of PFN ceramics examined by X-ray diffraction was found to be perovskite-like. Microstructural examinations, the electric conductivity and tests of the ferroelectric and magnetic properties were performed. The magnetic susceptibility measurements have shown that the samples show an antiferromagnetic transition at high temperature (T N1) and it is followed by an antiferromagnetic like transition at low temperature (T N2). It has been shown that in the technological process used the optimum compacting conditions are revealed by the ceramics sintered at 1050 • C for 2 h.

Research paper thumbnail of Electrophysical Properties of PZT-Type Ceramics Obtained by Two Sintering Methods

Applied Sciences

This study demonstrates the impact of two sintering techniques on the fundamental properties of d... more This study demonstrates the impact of two sintering techniques on the fundamental properties of doped PZT-type ceramic materials (with Mn4+, Sb3+, Gd3+, and W6+), with the general chemical formula Pb(Zr0.49Ti0.51)0.94Mn0.021Sb0.016Gd0.012W0.012O3. The synthesis of ceramic powders was carried out through the calcination method. Two different methods were used in the final sintering process: (i) pressureless sintering (PS) and (ii) hot pressing (HP). The PZT-type ceramics were subjected to electrophysical measurements, encompassing various analyses such as X-ray diffraction (XRD), microstructure (scanning electron microscopy (SEM)), ferroelectric and dielectric properties, and DC electrical conductivity. The analysis of the crystal structure at room temperature showed that the material belongs to the perovskite structure from the tetragonal phase (P4mm space group) without foreign phases. Both sintering methods ensure obtaining the material with appropriate dielectric and ferroelectri...

Research paper thumbnail of Magnetoelectric Composites: Engineering for Tunable Filters and Energy Harvesting Applications

Applied Sciences

Multiferroic ceramic composites have been engineered to incorporate multiple desired physical pro... more Multiferroic ceramic composites have been engineered to incorporate multiple desired physical properties within a single ceramic component. The objective of this study was to create such composites through pressure less sintering ferroelectric-doped PZT and nickel–zinc ferrite at a temperature of 1250 °C. The growth of ferrite grains was found to be influenced by the concentration of the ferroelectric PZT phase. Consequently, an increase in the ferrite content decreased the average particle size of nickel–zinc ferrite by a factor of 1.8. After impedance spectroscopy, the multiferroic ceramic composites can be categorized into two groups: those with low ferrite content (<20%) and those with a high ferrite content (>20%). Composites with a high ferrite content are suitable for dual-band filters or shield applications. The impedance spectroscopy analysis revealed that the resonance frequency can be shifted to higher frequency ranges. Therefore, it was demonstrated that modifying ...

Research paper thumbnail of The Magnetic and Electric Measurements of the Multiferroic PbFe1/2Nb1/2O3 Ceramics Obtained Using Hot Uniaxial Pressure Method

Archives of Metallurgy and Materials

We present the results of investigations of Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ceramic samples obtained u... more We present the results of investigations of Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ceramic samples obtained using two-step synthesis (i.e. columbite method). For obtained samples complex investigations of microstructure, magnetic and electrophysical properties have been performed at low and at high temperatures. Microstructure is characterized by small grains with high homogeneity and high density (low porosity). Impedance of samples and the phase shift angle have been measured using LCR Meter. Next the AC electric conductivity, dielectric permittivity and loss tangent have been calculated. AC conductivity at frequency 3 Hz was measured in similar way using Quantum Design PPMS System in magnetic fields 1000 Oe and 10000 Oe. At temperature range 240K-260K the anomalies of conductivity are observed. These anomalies depend on measuring cycle (heating, cooling) and magnetic field.

Research paper thumbnail of Obtaining and Main Dielectric Properties of Ba0.6Pb0.4TiO3/graphene Oxide Composite

In this paper there is described the technology of obtaining and results of investigations of mic... more In this paper there is described the technology of obtaining and results of investigations of microstructure, XRD, SEM, main dielectric properties, electrical conductivity measurements and P-E hysteresis loops of Ba0.6Pb0.4TiO3/graphene oxide composite (abbr. BPT/GO). In the final step of technology, the samples have been sintered using the Spark Plasma Sintering (SPS) method. Diffraction patterns of BPT/GO composite exhibit lines which can be related with perovskite structure, as well as reveal additional lines that can be derived from the initial component oxides. Investigations of electrical conductivity suggest that the PTCR effect occurs at temperatures up to about 120°C. Dielectric hysteresis loops below 90°C are wide and typical for materials with rather high electrical conductivity. The hysteresis loop obtained at 120°C is more typical for ferroelectrics. The obtained material is interesting, however it is probably possible to find better conditions of obtaining it and/or a ...

Research paper thumbnail of Basic properties of the PFN ceramic doped by potassium

Research paper thumbnail of Podstawowe właściwości ceramiki PFN domieszkowanej potasem

In the work, PFN ceramics were obtained by a one-step synthesis. The ceramics were modio ed with ... more In the work, PFN ceramics were obtained by a one-step synthesis. The ceramics were modio ed with the help of potassium incorporated in an amount of 1.0%, 2.0%, 3.0%, 4.0% and 6.0 mol%. Effects of the potassium dopant on the crystal structure, microstructure and main properties of the PFN ceramics were studied. It has been shown that the heterovalence doping of PFN by the potassium in the amount of 2.0-4.0 mol%. had a positive effect on the density and microstructural homogeneity of the ceramic samples. Such a potassium admixture limited the formation of the non-ferroelectric (pirochlore) phase during the technological process. Measurements of dielectric properties of the doped compositions have shown that potassium causes a decrease of the maximum permittivity and reduces slightly the degree of blur of the phase transition. There is also an increase in the dielectric loss and electrical conductivity. There was no a clear trend in the effect of the incorporated potassium additive on ...

Research paper thumbnail of Wpływ koncentracji PbTiO3 na podstawowe parametry piezoelektryczne nanoceramiki PZT

Research paper thumbnail of Struktura i właściwości fizyczne ceramiki 46/54 PZT modyfikowanej strontem, chromem i neodymem

Research paper thumbnail of Multi-component PZT ceramics obtained by mechanochemical activation and conventional ceramic technology

Journal of Thermal Analysis and Calorimetry, 2019

In the paper, the multi-component PZT-type ceramics doped with Mn 4+ , Sb 3+ , W 6+ and Ni 2+ wer... more In the paper, the multi-component PZT-type ceramics doped with Mn 4+ , Sb 3+ , W 6+ and Ni 2+ were investigated. The following chemical composition was selected: Pb(Zr 0.49 Ti 0.51) 0.94 Mn 0.01 Sb 0.03 W 0.015 Ni 0.01 O 3. The ceramic powders were synthesized by two methods: (i) the classical technological method using powder calcination and (ii) mechanochemical synthesis at room temperature. Densification of the powders (sintering) was carried by free sintering method. In the case of the mechanochemical activation, the development of the synthesis has been monitored by XRD and SEM investigations after different milling periods (25 h, 50 h and 75 h). From the obtained powder, the bulk ceramic samples have been prepared by uniaxial pressing and subsequent sintering. The ceramic multi-component PZT-type samples were characterized in wide temperature range by DTA, TG, DC electrical conductivity, XRD, SEM and EDS (energy-dispersive spectrometry) methods, and their ferroelectric, dielectric and piezoelectric properties were studied. At the work, a comparison of test results for samples obtained by two methods was made. The X-ray investigations confirmed that the obtained material exhibits a perovskite-like structure with a tetragonal phase (close to the morphotropic area). The detailed results of the multi-component PZT-type ceramics predispose these materials in microelectronic applications, for example, as element of the actuators and piezoelectric transducers. The application of the mechanochemical synthesis to obtain the PZT-type materials allows to shorten the time of the technological process, and at the same time not to reduce the electrophysical properties of ceramic samples.

Research paper thumbnail of High-density lead-free K0.5Bi0.5TiO3 ceramics: preparation, mechanical and dielectric properties

Phase Transitions, 2018

The preparation of high-density lead-free potassium-bismuth titanate K 0.5 Bi 0.5 TiO 3 about 96-... more The preparation of high-density lead-free potassium-bismuth titanate K 0.5 Bi 0.5 TiO 3 about 96-98% of the calculated density (X-ray), confirmed by the Archimedes method, is presented. All stages of the technological process are explained in detail. The control of microstructure was performed by scanning electron microscopy. The crystal structure and phase content of samples were determined by X-ray diffraction at each stage of sintering. Four types of samples were obtained under various technological conditions. The ultrasonic measurements of the obtained samples were carried out and basic parameters were determined, such as Young and Kirchoff modulus and Poisson's ratio were determined at room temperature. The dielectric measurements show that the maximum value of dielectric permittivity is shifted towards higher temperatures as the frequency increases. This feature is characteristic of ferroelectric relaxor materials. The presented materials can be a good starting point for the development of lead-free ceramics.

Research paper thumbnail of Magnetoelectric and electric measurements of the (1− x )BiFeO 3 –( x )Pb(Fe 1/2 Nb 1/2 )O 3 solid solutions

Materials Chemistry and Physics, 2017

Highlights  BF-PFN samples have a densely packed microstructure, with well crystallized grains. ... more Highlights  BF-PFN samples have a densely packed microstructure, with well crystallized grains.  Bi atoms possibly migrate from BF toward PFN component during sintering.  BF-PFN have a diffuse character of the ferroelectric-paraelectric phase transition.  Magnetoelectric coefficient ( ME) for BF-PFN is higher, than for pure BF.  The  ME for BF-PFN is about three times higher than for 0.75BiFeO 3-0.25BaTiO 3 .

Research paper thumbnail of The Positive Temperature Coefficient of Resistivity Effect in the Pb(Fe1/2Nb1/2)O3Ceramics Admixed with Lithium

Acta Physica Polonica A, 2009

In the paper technological conditions were looked for to obtain the Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ce... more In the paper technological conditions were looked for to obtain the Pb(Fe 1/2 Nb 1/2)O 3 (PFN) ceramics and the PFN ceramics with the lithium admixture with the highest electric conduction and conditions appropriate for the PTC-R effect formation. Measurements of dc electrical resistivity, dielectric permittivity and dielectric loss were made as functions of temperature from room temperature to 190 • C, at 1 kHz. The best set of values of dielectric loss and dielectric constant, from the ferroelectricity point of view, were obtained when the precursor with orthorhombic structure was employed. By creating appropriate technological conditions in the PFN ceramics the PTC-R effect can occur above the Curie temperature. Their electric properties are determined by presence of a basic phase of the potential barrier on the grain boundaries.

Research paper thumbnail of Technology and Main Properties of PMN-PT-Ferrite Multiferroic Ceramic Composite Materials

7th Forum on New Materials - Part B, 2016

In the presented work composite ferroelectric/ferrimagnetic ceramics have been obtained and descr... more In the presented work composite ferroelectric/ferrimagnetic ceramics have been obtained and described. The investigated material is based on PMN-PT powders and Ni-Zn ferrite powder. The Powders of ferroelectric component (i.e. (1–x)PMN-(x)PT with x from 0.25 to 0.40 with step 0.03 were synthesized using the sol-gel method. The magnetic component i.e. nickel-zinc ferrite was obtained from oxides using the classic method of obtaining ceramics. The compositions of PMN–PT used by us have rhombohedral or tetragonal symmetries, or belong to morphotropic region. The final ceramic composite samples were obtained using the classic method of ceramic technology with calcination route and final pressureless densification using free sintering. In this paper, XRD, EDS dielectric and magnetic properties have been investigated and described for the obtained composite ceramic samples.

Research paper thumbnail of The Basic Properties of the Ferroelectromagnetic Composites Based on the Ferrite and PZT-Type Powders

Advances in Science and Technology, 2016

In this paper a ferroelectric–ferromagnetic composites based on a doped PZT-type and ferrite powd... more In this paper a ferroelectric–ferromagnetic composites based on a doped PZT-type and ferrite powders were presented. Ferroelectric powder (in amount of 85.0 wt-%) was based on multicomponent PZT-type materials: i) Pb(Zr0.51Ti0.49)O3+0.2%at.Bi2O3+0.03%at.Nb2O5+ 0.06%at.MnO2, ii) Pb0.84Ba0.16(Zr0.54Ti0.46)O3+1.0%at.Nb2O5, while nickel–zinc ferrite Ni0.64Zn0.36Fe2O4 (in amount of 15.0 wt-%) served as the magnetic component of the composite samples. The synthesis of the ferroelectric–ferromagnetic composite’s powders was performed by solid state method, while final densification of the synthesized powders was achieved using free sintering method.Conducted basic tests indicate that obtained ferroelectromagnetic ceramic composites (PZT-ferrite type) exhibit good properties giving the possibility to use them to construct magnetoelectric transducers.

Research paper thumbnail of Dielectric properties of the PZT ceramics obtained by the sol-gel method and doped by chromim, manganium and tantalum

Materialy Ceramiczne Ceramic Materials, 2014

In this paper we obtained multicomponent PZT ceramics doped by chromium, manganese and tantalum o... more In this paper we obtained multicomponent PZT ceramics doped by chromium, manganese and tantalum oxides. Ceramic powder with a composition of Pb(Zr0,70Ti0,30)O3 was synthesized by the sol-gel method. In the next step, the powder was doped by an oxide: Cr2O3, MnO2 or Ta2O5. Two compositions of ceramic powders were obtained with constant amounts of manganese (1.0%) and chromium (0.15%) oxides, but with different percentages of tantalum oxide (0.03% and 0.05%). Synthesis of the materials was carried out by solid phase reaction, using calcination of powder compacts compacting method, while the sintering was performed by two methods: free sintering (FS) - with no pressure, and hot pressing (HP). For the obtained ceramic samples, microstructural, X-ray, EDS, basic dielectric property and electrical hysteresis loop investigations were carried out. The studies have shown that the use of the hot pressing method allows obtaining the materials with higher values of maximum electric permittivity, but with higher values of dielectric losses, when compared with the FS obtained ones. The doping of the basic PZT composition by tantalum, manganese and chromium oxides decreases the temperature of phase transition (Tm) and increases the ferroelectric hardness. The properties of multicomponent free sintered PZT ceramics permit its

Research paper thumbnail of Ferroelectromagnetic solid solutions on the base piezoelectric ceramic materials for components of micromechatronics

Mechanical Systems and Signal Processing, 2016

Abstract In the presented work, a ferroelectromagnetic solid solutions based on PZT and ferrite p... more Abstract In the presented work, a ferroelectromagnetic solid solutions based on PZT and ferrite powders have been obtained. The main aim of combination of ferroelectric and magnetic powders was to obtain material showing both electric and magnetic properties. Ferroelectric ceramic powder (in amount of 90%) was based on the doped PZT type solid solution while magnetic component was nickel–zinc ferrite Ni 1− x Zn x Fe 2 O 4 (in amount of 10%). The synthesis of components of ferroelectromagnetic solid solutions was performed using the solid phase sintering. Final densification of synthesized powder has been done using free sintering. The aim of the work was to obtain and examine in the first multicomponent PZT type ceramics admixed with chromium with the following chemical composition Pb 0.94 Sr 0.06 (Zr 0.46 Ti 0.54 )O 3 +0.25 at% Cr 2 O 3 and next ferroelectromagnetic solid solution based on a PZT type ferroelectric powder (Pb 0.94 Sr 0.06 (Zr 0.46 Ti 0.54 )O 3 +0.25 at% Cr 2 O 3 ) and nickel–zinc ferrite (Ni 0.64 Zn 0.36 Fe 2 O 4 ), from the point of view of their mechanical and electric properties, such as: electric permittivity, e ; dielectric loss, tanδ ; mechanical losses, Q −1 ; and Young modulus, E .

Research paper thumbnail of Influence of the Technology Conditions on the Mechanical and Dielectric Properties of the PZT-Base Piezoceramic Transducers

Solid State Phenomena, 2003

Application of the piezoceramics produced on the base of the PZT-type s olid solution in modern e... more Application of the piezoceramics produced on the base of the PZT-type s olid solution in modern electroacoustics depends primary on its mechanical and electr ica pa ameters. Multicomponent ceramic materials of the PZT-type are characterized by the occurrence of the morphotrophy area, it means the area of the rhombohedral and tetragonal phase coexistence. T he position and width of the area depends on the solid chemical solution and the technology used for obtai ning it. Therefore, selecting the suitable methods and conditions for producing piezoceramics is very impo tant since it has a direct influence on its properties. This work presents results of the investigations of the piezocerami c samples of the PZT-type received by the hot pressing method and the conventional sintering in different condi ions. The results obtained will be used to optimize the technological process and will indicate possibilities of wider applications of PZT-type piezoceramics in modern technology. Introduction Apart from the chemical composition and microstructure of ferroelec tric eramics temporary and temperature stability of their mechanical and dielectric param eters constitute important factors influencing their range of application. This has been confirmed by invest gations of the multicomponent solid state solutions of the PZT-type, conducted by differ ent methods [1 6]. Mechanical spectroscopy due to its high sensitivity to changes taking place in the real structure of materials has been more often used in recent investigations [6]. To observe changes occurring in the domain structure and to determine the stability of mechanical and die lectric parameters, the application of mechanical spectroscopy and the resonance-anti-resonance method is used. The influence of the conditions of the technological process on the stabil ity of temperature, on the mechanical properties and on the basic dielectric parameters of t he multicomponent piezoelectric ceramics of the PZT-type is shown. These investigations were ai m d at controlling the manufacturing process of ceramics to be used in ultrasound generators of high power e ngines and in piezoelectric transformers. Experimental The material used in this study was the ceramics belonging to te rnary solid solutions of the PZT-type with the following chemical composition: Pb (Zr 0.51 Ti0.49) O3 + Pb (Nb0.5 Mn0.5) O3 + 2.15 wt % Bi 2O3; its dielectric parameters show that it belongs to ceramics of medium ferroe lect ic hardness. The ceramics was obtained in different technological conditions by the hot pressing method in nitrogen or in argon atmosphere, and by the classical sintering method. A synthesized powder of the Solid State Phenomena Online: 2003-02-13 ISSN: 1662-9779, Vol. 89, pp 303-308 doi:10.4028/www.scientific.net/SSP.89.303 © 2003 Trans Tech Publications Ltd, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (Semanticscholar.org-18/03/20,14:08:25) ceramics was used to manufacture the investigated ceramics. In the hot pressing technology 25 MPa pressure was used and moulded pieces were sintered for 1h at 1473 K. In the classical sintering method the sintering temperature was 1523 K while the sintering time was 2 h. After completing the technological process all specimens were ground and polished. Electrodes on all specimens were formed by the silver paste burning method. The obtained samples were subjected to polarization using the low te mperature method at 432 K for 30 min; the intensity of the polarization field was E p = 35 kV/cm. After completing the polarization process measurements of dielectric values in the temperature depe ndenc function were performed by an automatic capacity bridge of a Tesla BM 595 type at the meas urement field frequency of 1 kHz. Stability tests of dielectric parameters were carried out in the temper atur range from 273 K to 423 K. Measurements of mechanical properties performed by a rezonant mecha nical spectrometer of the RAK-2 type, enabled us to measure the temperature dependences of the i nternal friction and of the dynamic Young’s modulus [7]. Young’s modulus, the transverse elasticity m odulus, and Poisson’s’ coefficient (ν) were determined by the UMT-11 ultrasonic flaw detector [8]. The phase analysis of the investigated ceramics was carried out in an X-ray diffractome er (H2G-4B type). It was found that at room temperature the ceramics had a tetragonal structure with t he following lattice constants: a o = 4.076 Å, co = 4.114 Å, and an elementary cell deformation parameter sigma δT = 0.9 %. Results and Discussion Figure 1 presents selected examples of temperature dependence of t he electric permittivity ε and the dielectric loss tg δ for the ceramics formed in different technological conditions. It c an be seen that the ceramics obtained by the classical method exhibits a phase…

Research paper thumbnail of Nano-indentation studies and macro-scale mechanical testing of vanadium modified BBN ceramics

World Journal of Engineering, 2012

The mechanical properties of the pure as well as vanadium modified BaBi2Nb2O9 ceramics have been ... more The mechanical properties of the pure as well as vanadium modified BaBi2Nb2O9 ceramics have been studied in macro and nano-scales using three different methods. Specifically for macro-scale, ultrasonic velocity and internal friction were employed to evaluate the Young modulus (E), whereas for nano-scale the nanoindentation method was a very useful tool to obtain the elastic modulus and hardness. These results reveal the strong influence of vanadium admixture on mechanical properties of the discussed material. In the case of modified ceramics the value of Young modulus increases, which is probably connected with the decreasing of the number of defects. Moreover, the described results show the significant differences in mechanical properties measured on nano and macro-scale. It is concluded that the knowledge of the mechanical properties of the ceramic material is complete only when we take into account both the macro and nano-scale.

Research paper thumbnail of Ferroelectric and magnetic properties of ferroelectromagnetic PbFe1/2Nb1/2O3 type ceramics

Journal of Magnetism and Magnetic Materials, 2011

PbFe 1/2 Nb 1/2 O 3 (PFN) ceramics, to which an admixture of manganese oxide (MnO 2) was added, w... more PbFe 1/2 Nb 1/2 O 3 (PFN) ceramics, to which an admixture of manganese oxide (MnO 2) was added, was obtained by calcination of the powder in a single stage synthesis. Compacting was made by a free sintering method. Results of investigations of microstructure, magnetic, magnetoelectric, dielectric and piezoelectric properties and electric conductivity vs. temperature are presented. The influence of manganese admixture on the physical properties of the PFN ceramics is presented. The admixtures decrease the electric conduction of the PFN ceramic specimens.

Research paper thumbnail of Magnetic and ferroelectric properties of PbFe1/2Nb1/2O3 synthesized by a solution precipitation method

Journal of Alloys and Compounds, 2010

Results of an influence of the technological conditions on ferroelectric and magnetic properties ... more Results of an influence of the technological conditions on ferroelectric and magnetic properties of the PbFe 1/2 Nb 1/2 O 3 ceramics (PFN) are presented. Synthesizing of the PFN material was made by a chemical solution precipitation method and sintering (compacting) by a free sintering method. Temperatures of dehydratization, burning of an organic phase and crystallization of an amorphous powder were determined by the thermal analysis (TA) method. The structure of PFN ceramics examined by X-ray diffraction was found to be perovskite-like. Microstructural examinations, the electric conductivity and tests of the ferroelectric and magnetic properties were performed. The magnetic susceptibility measurements have shown that the samples show an antiferromagnetic transition at high temperature (T N1) and it is followed by an antiferromagnetic like transition at low temperature (T N2). It has been shown that in the technological process used the optimum compacting conditions are revealed by the ceramics sintered at 1050 • C for 2 h.