Dr. R.B. Tangsali - Academia.edu (original) (raw)
Papers by Dr. R.B. Tangsali
INTRODUCTION Nanoparticle Mn-Zn ferrite material classified as spinel ferrites find applications ... more INTRODUCTION Nanoparticle Mn-Zn ferrite material classified as spinel ferrites find applications in electronics, optoelectronics, refrigeration, magnetic recording media, sensors, temperature sensitive ferrofluids, energy conversion devices and power devices especially for electromagnetic interference suppression (EMIS) etc. The properties of ferrite nanoparticles depend on factors like particle size, surface area to volume ratio, cation distribution, and impurities as well as the properties of dopant material. Some of these can be directly linked to the method adopted for sample preparation as the particle size of the particles in the sample as well as crystallinity of the sample truly depend on the method of sample preparation. Several methods such as combustion synthesis, co-precipitation method, hydrothermal precipitation processing and sol–gel synthesis have been proposed and employed successfully to prepare ferrite nanoparticles. It has been observed that gamma radiation and d...
Materials Chemistry and Physics, 2017
Advanced Science, Engineering and Medicine, 2016
Advanced Science Letters, 2016
Advanced Science Letters, 2016
Advanced Science Letters, 2016
Journal of Materials Science: Materials in Electronics, 2019
Zn (1−x) Co x O nanoparticles with (x = 0.05, 0.10, 0.15 and 0.20) were prepared by combustion me... more Zn (1−x) Co x O nanoparticles with (x = 0.05, 0.10, 0.15 and 0.20) were prepared by combustion method. Here we report our findings on electrical properties carried out on these materials from room temperature to 500 °C. Thermopower investigations carried out on the materials resulted in Seebeck coefficient showing a transition from positive to negative values with 'x' dependent enhancements. The material that exhibits a p-type semiconductor character at room temperature translates into an n-type of semiconductor at higher temperatures beyond 90 °C marked by a first order transition. Electrical resistivity and the activation energy being interrelated are seen to decrease with rising temperature due to increase in charge carrier concentration. Dielectric constant (ε) and dielectric loss (tan δ) investigated as a function of frequency showed nearly exponential decline in their values with increasing frequency for all the samples. However temperature dependent 'ε' and 'tan δ' show a peaking behaviour at lower temperatures with increasing trend at higher temperature as a result of increase in dielectric polarization. The DMS materials being ferromagnetic at room temperature are good temperature dependent semiconductors with high dielectric constant.
Journal of Superconductivity and Novel Magnetism, 2018
Variations of Curie temperature and strength of magnetic phases with sintering temperature and Ni... more Variations of Curie temperature and strength of magnetic phases with sintering temperature and Ni concentration is investigated in the present work. The AC susceptibility studies show a decrease in Curie temperature (TC) with an increase in Ni concentration in the samples. Comparison of Curie temperatures with the reported results reveals that samples in the present work show higher TC enabling high thermal stability. The Mössbauer spectra of nano-and sintered Ni-Zn ferrite samples were recorded at room temperature to monitor the local environment around Fe cations through Mössbauer hyperfine parameters as a function of composition and sintering temperatures. The increase in sharpness of the Mössbauer sextet with an increase in Ni concentration and sintering temperature corroborate improvement in homogeneity and ferrimagnetic ordering. The results of hyperfine parameters offer the possibility of having close view on configuring Curie temperature through monitoring hyperfine field by altering sintering temperature and/or Ni concentration. As the temperature dependence of magnetic and magnetoelastic properties is strongly influenced by the Curie temperature, the successful possible configuration of Curie temperature in the present work can be further investigated for desired sensor applications.
Journal of Superconductivity and Novel Magnetism, 2018
Single-phase nano-Ni-Zn ferrite samples in the range of 6 to 75 nm were synthesized using microwa... more Single-phase nano-Ni-Zn ferrite samples in the range of 6 to 75 nm were synthesized using microwave-assisted combustion method. Enhancement of saturation magnetization (M s) was observed in comparison with previously reported results. Minor variation of (M s) due to composition change can be explained on the basis of strengthening of A-B exchange interaction due to replacement of nonmagnetic Zn ions by Ni ions. Low coercivity (H c) and retentivity (M r) indicate low loss in the samples. SQUID analysis showed that the blocking temperature (T B) of the samples can be tailored in the present work.
Materials Chemistry and Physics, 2017
Ultrafine nanopowders of Mn 0.6 Zn 0.4 Fe 2-x Nd x O 4 (x = 0, 0.04, 0.06, 0.08, and 0.1) were pr... more Ultrafine nanopowders of Mn 0.6 Zn 0.4 Fe 2-x Nd x O 4 (x = 0, 0.04, 0.06, 0.08, and 0.1) were prepared using combustion method. The influence of Nd +3 doping on structural parameters, morphological characteristics and magnetic properties were investigated. Formation of pure spinel phase was confirmed using X-ray powder diffraction (XRPD). Nd +3 doping in Mn-Zn ferrite samples have shown remarkable influence on all the properties that were under investigation. An increase in lattice constant commensurate with increasing Nd +3 concentrations was observed in the samples. The crystallite size calculated from XRPD data and grain size observed from Transmission Electron Microscope showed a proportionate decrement with increment in rare earth doping. An increase in mass density, X-ray density, particle strain and decrease in porosity were the other effects noticed on the samples as a result of Nd +3 doping. The corresponding tetrahedral, octahedral bond lengths and bond angles estimated from XRPD data have also shown substantial influence of the Nd +3 doping. Magnetic parameters namely saturation magnetization (M S) and net magnetic moment B , estimated using vibrating sample magnetometer (VSM) were found to depend on the Nd +3 doping. Mössbauer spectroscopy was employed to study the magnetic environment of Mössbauer active ions and detection of superparamagnetic behavior in nanocrystalline rare earth ferrite material. The isomer shift values obtained from Mössbauer spectra indicate the presence of Fe +3 ions at tetrahedral site (A-site) and octahedral site (B-site), respectively.
Journal of Superconductivity and Novel Magnetism, 2015
Nanoparticles of MnxZn(1−x)Fe2O4 with x = 0.5, 0.6, 0.7, 0.8 were prepared for the first time wit... more Nanoparticles of MnxZn(1−x)Fe2O4 with x = 0.5, 0.6, 0.7, 0.8 were prepared for the first time with metal oxides as raw material, using simple inexpensive combustion technique at low temperature. Formation of nanoparticle material was confirmed from X-ray diffraction (XRD) data and transmission electron microscopy (TEM) micrographs. Magnetic measurements, carried out with VSM, SQUID, and AC susceptibility equipment, show formation of samples with single-domain grains as well as samples with multidomain grains. A large shift in superparamagnetic blocking temperature, below room temperature with increasing magnetic field, was also observed.
Journal of Superconductivity and Novel Magnetism, 2015
The powder of Ni 0.40 Zn 0.60 Fe 2 O 4 nanoparticles is synthesized using a microwave-assisted co... more The powder of Ni 0.40 Zn 0.60 Fe 2 O 4 nanoparticles is synthesized using a microwave-assisted combustion method. X-ray diffraction and IR spectrum analysis show that the sample has a single-phase spinel structure. Debye-Scherrer formula reveals a crystallize size of 49 nm ±5 %, whereas transmission electron microscopy (TEM) results show particle sizes in the range of 10 to 60 nm. Superparamagnetic nature of the sample was confirmed from a close hysteresis loop. The Curie temperature (T C) was found to be 422 • C and 30 K as a blocking temperature.
Journal of Magnetism and Magnetic Materials, 2015
Nanoparticle magnetic materials are suitable for multiple modern high end medical applications li... more Nanoparticle magnetic materials are suitable for multiple modern high end medical applications like targeted drug delivery, gene therapy, hyperthermia and MR thermometry imaging. Majority of these applications are confined to use of Mn-Zn ferrite nanoparticles. These nanoparticles are normally left in the body after their requisite application. Preparing these nanoparticles is usually a much involved job. However with the development of the simple technique Mn x Zn 1 À x Fe 2 O 4 nanoparticles could be prepared with much ease. The nanoparticles of Mn x Zn 1 À x Fe 2 O 4 with (x ¼1.0, 0.7, 0.5, 0.3, 0.0) were prepared and irradiated with gamma radiation of various intensities ranging between 500 R to 10,000 R, after appropriate structural and magnetic characterization. Irradiated samples were investigated for structural and magnetic properties, as well as for structural stability and cation distribution. The irradiated nanoparticles exhibited structural stability with varied cation distribution and magnetic properties, dependent on gamma radiation dose. Surprisingly samples also exhibited quenching of lattice parameter and particle size. The changes introduced in the cation distribution, lattice constant, particle size and magnetic properties were found to be irreversible with time lapse and were of permanent nature exhibiting good stability even after several months. Thus the useful properties of nanoparticles could be enhanced on modifying the cation distribution inside the nanoparticles by application of gamma radiation.
International Journal of Nanoscience, 2004
Nitrilotriacetate precursors have been used for synthesis of oxide materials. High permeability M... more Nitrilotriacetate precursors have been used for synthesis of oxide materials. High permeability Mn – Zn ferrite with general formula Mn x Zn 1-x Fe 2 O 4 where x=0.3/0.35/0.4/0.45/0.5/0.55/0.6/0.65/0.7 were prepared using this novel method. Formation of cubic spinel structure was confirmed by XRD, which also provided information on formation of fine particle material. The magnetic properties of these materials were investigated after sintering the same at 950°C, 1150°C, 1250°C and 1350°C in nitrogen atmosphere and at 1050°C in air and were found to be interesting.
International Journal of Nanotechnology, 2011
The amazing magnetic properties exhibited by nanoparticles Mn-Zn ferrites and their promising tec... more The amazing magnetic properties exhibited by nanoparticles Mn-Zn ferrites and their promising technological and medical applications have attracted much interest in recent years. Nanoparticle Mn x Zn (1-x) Fe 2 O 4 spinel ferrites with x = 0.6/0.63/0.65/0.67/0.7 were synthesised by the nitrilotriacetate precursor method employing microwave combustion synthesis. Powder X-ray diffractometry (XRD) confirmed the formation of the ferrite phase in all samples. IR analysis was done to verify formation of spinel structure. Elemental analysis using EDS confirmed the nanoparticle composition. The crystallite size was calculated from peak widths using the Scherrer formula, yielding a size in the range of 10-25 nm. Transmission electron microscopy was also performed on the samples to testify formation of nanosized crystallites in the sample. Saturation magnetisation (Mr), retentivity (Ms) and coercivity (Hc) measurements were carried out on the samples using standard hysteresis
ABSTRACT Nanoparticles Ni0.55Zn0.45Fe2O4 was synthesized at low temperature using novel precursor... more ABSTRACT Nanoparticles Ni0.55Zn0.45Fe2O4 was synthesized at low temperature using novel precursor method. The single spinel phase crystallization of sample was confirmed using XRD and IR spectra. Nanosize particles were confirmed using XRD and TEM images. Isomer shift in Mossbauer spectral studies are consistent with Fe ions in trivalent state. DC resistivity was of the order of 108 ohm cm that is two orders higher than those reported for NiZn ferrites prepared by conventional ceramic method. The high resistivity was attributed to nanosize particles, absence of Fe+2 ions and method of preparation.
International Journal of Thin Films Science and Technology, 2014
MnxZn1-xFe2O4 nanoparticles were chemically synthesized by co- precipitating metal ions in alkali... more MnxZn1-xFe2O4 nanoparticles were chemically synthesized by co- precipitating metal ions in alkaline aqueous solutions. The XRD peaks match up to spinel ferrites without any multi phase indication and clear visibility of ferrite FT-IR absorption bands confirm single phase spinal formation. Particle size derived from XRD data is authenticated by TEM micrographs. Thin films fabricated from this material on quartz substrate by pulse laser deposition were characterised using XRD. The XRD data revealed formation of spinel structure with a reasonable degree of texture. AFM analysis confirms nano granular film morphology with dimensions comparable to that of target grain. Magnetic data obtained from textured nanocrystalline Mn-Zn ferrite thin film measurements made known enhanced coercivity. The observed enhanced coercivity is explained with due consideration of film texture and surface disorder that originated from Mn concentration specific initial adsorption prior to nucleation, resulting in directional film growth.
Physica B: Condensed Matter, 2015
Nanoparticles of Mn 0.2 Zn 0.8 Fe 2 O 4 were chemically synthesized by co-precipitating the metal... more Nanoparticles of Mn 0.2 Zn 0.8 Fe 2 O 4 were chemically synthesized by co-precipitating the metal ions in aqueous solutions in a suitable alkaline medium. The identified XRD peaks confirm single phase spinal formation. The nanoparticle size authentication is carried out from XRD data using Debye Scherrer equation. Thin film fabricated from this nanomaterial by pulse laser deposition technique on quartz substrate was characterized using XRD and Raman spectroscopic techniques. XRD results revealed the formation of high degree of texture in the film. AFM analysis confirms nanogranular morphology and preferred directional growth. A high deposition pressure and the use of a laser plume confined to a small area for transportation of the target species created certain level of porosity in the deposited thin film. Magnetic property measurement of this highly textured nanocrystalline Mn-Zn ferrite thin film revealed enhancement in properties, which are explained on the basis of texture and surface features originated from film growth mechanism.
Nanoparticles of Ni0.45Zn0.55Fe2O 4 were chemically synthesized by novel precursor method at low ... more Nanoparticles of Ni0.45Zn0.55Fe2O 4 were chemically synthesized by novel precursor method at low temperature. Average particles size was found to be 37 nm. The Mössbauer spectroscopy studies were carried out on the sample for the investigation of magnetic and structural arrangement of Fe in the nano-crystalline ferrite samples. The values of isomer shift are consistent with Fe ions in trivalent
INTRODUCTION Nanoparticle Mn-Zn ferrite material classified as spinel ferrites find applications ... more INTRODUCTION Nanoparticle Mn-Zn ferrite material classified as spinel ferrites find applications in electronics, optoelectronics, refrigeration, magnetic recording media, sensors, temperature sensitive ferrofluids, energy conversion devices and power devices especially for electromagnetic interference suppression (EMIS) etc. The properties of ferrite nanoparticles depend on factors like particle size, surface area to volume ratio, cation distribution, and impurities as well as the properties of dopant material. Some of these can be directly linked to the method adopted for sample preparation as the particle size of the particles in the sample as well as crystallinity of the sample truly depend on the method of sample preparation. Several methods such as combustion synthesis, co-precipitation method, hydrothermal precipitation processing and sol–gel synthesis have been proposed and employed successfully to prepare ferrite nanoparticles. It has been observed that gamma radiation and d...
Materials Chemistry and Physics, 2017
Advanced Science, Engineering and Medicine, 2016
Advanced Science Letters, 2016
Advanced Science Letters, 2016
Advanced Science Letters, 2016
Journal of Materials Science: Materials in Electronics, 2019
Zn (1−x) Co x O nanoparticles with (x = 0.05, 0.10, 0.15 and 0.20) were prepared by combustion me... more Zn (1−x) Co x O nanoparticles with (x = 0.05, 0.10, 0.15 and 0.20) were prepared by combustion method. Here we report our findings on electrical properties carried out on these materials from room temperature to 500 °C. Thermopower investigations carried out on the materials resulted in Seebeck coefficient showing a transition from positive to negative values with 'x' dependent enhancements. The material that exhibits a p-type semiconductor character at room temperature translates into an n-type of semiconductor at higher temperatures beyond 90 °C marked by a first order transition. Electrical resistivity and the activation energy being interrelated are seen to decrease with rising temperature due to increase in charge carrier concentration. Dielectric constant (ε) and dielectric loss (tan δ) investigated as a function of frequency showed nearly exponential decline in their values with increasing frequency for all the samples. However temperature dependent 'ε' and 'tan δ' show a peaking behaviour at lower temperatures with increasing trend at higher temperature as a result of increase in dielectric polarization. The DMS materials being ferromagnetic at room temperature are good temperature dependent semiconductors with high dielectric constant.
Journal of Superconductivity and Novel Magnetism, 2018
Variations of Curie temperature and strength of magnetic phases with sintering temperature and Ni... more Variations of Curie temperature and strength of magnetic phases with sintering temperature and Ni concentration is investigated in the present work. The AC susceptibility studies show a decrease in Curie temperature (TC) with an increase in Ni concentration in the samples. Comparison of Curie temperatures with the reported results reveals that samples in the present work show higher TC enabling high thermal stability. The Mössbauer spectra of nano-and sintered Ni-Zn ferrite samples were recorded at room temperature to monitor the local environment around Fe cations through Mössbauer hyperfine parameters as a function of composition and sintering temperatures. The increase in sharpness of the Mössbauer sextet with an increase in Ni concentration and sintering temperature corroborate improvement in homogeneity and ferrimagnetic ordering. The results of hyperfine parameters offer the possibility of having close view on configuring Curie temperature through monitoring hyperfine field by altering sintering temperature and/or Ni concentration. As the temperature dependence of magnetic and magnetoelastic properties is strongly influenced by the Curie temperature, the successful possible configuration of Curie temperature in the present work can be further investigated for desired sensor applications.
Journal of Superconductivity and Novel Magnetism, 2018
Single-phase nano-Ni-Zn ferrite samples in the range of 6 to 75 nm were synthesized using microwa... more Single-phase nano-Ni-Zn ferrite samples in the range of 6 to 75 nm were synthesized using microwave-assisted combustion method. Enhancement of saturation magnetization (M s) was observed in comparison with previously reported results. Minor variation of (M s) due to composition change can be explained on the basis of strengthening of A-B exchange interaction due to replacement of nonmagnetic Zn ions by Ni ions. Low coercivity (H c) and retentivity (M r) indicate low loss in the samples. SQUID analysis showed that the blocking temperature (T B) of the samples can be tailored in the present work.
Materials Chemistry and Physics, 2017
Ultrafine nanopowders of Mn 0.6 Zn 0.4 Fe 2-x Nd x O 4 (x = 0, 0.04, 0.06, 0.08, and 0.1) were pr... more Ultrafine nanopowders of Mn 0.6 Zn 0.4 Fe 2-x Nd x O 4 (x = 0, 0.04, 0.06, 0.08, and 0.1) were prepared using combustion method. The influence of Nd +3 doping on structural parameters, morphological characteristics and magnetic properties were investigated. Formation of pure spinel phase was confirmed using X-ray powder diffraction (XRPD). Nd +3 doping in Mn-Zn ferrite samples have shown remarkable influence on all the properties that were under investigation. An increase in lattice constant commensurate with increasing Nd +3 concentrations was observed in the samples. The crystallite size calculated from XRPD data and grain size observed from Transmission Electron Microscope showed a proportionate decrement with increment in rare earth doping. An increase in mass density, X-ray density, particle strain and decrease in porosity were the other effects noticed on the samples as a result of Nd +3 doping. The corresponding tetrahedral, octahedral bond lengths and bond angles estimated from XRPD data have also shown substantial influence of the Nd +3 doping. Magnetic parameters namely saturation magnetization (M S) and net magnetic moment B , estimated using vibrating sample magnetometer (VSM) were found to depend on the Nd +3 doping. Mössbauer spectroscopy was employed to study the magnetic environment of Mössbauer active ions and detection of superparamagnetic behavior in nanocrystalline rare earth ferrite material. The isomer shift values obtained from Mössbauer spectra indicate the presence of Fe +3 ions at tetrahedral site (A-site) and octahedral site (B-site), respectively.
Journal of Superconductivity and Novel Magnetism, 2015
Nanoparticles of MnxZn(1−x)Fe2O4 with x = 0.5, 0.6, 0.7, 0.8 were prepared for the first time wit... more Nanoparticles of MnxZn(1−x)Fe2O4 with x = 0.5, 0.6, 0.7, 0.8 were prepared for the first time with metal oxides as raw material, using simple inexpensive combustion technique at low temperature. Formation of nanoparticle material was confirmed from X-ray diffraction (XRD) data and transmission electron microscopy (TEM) micrographs. Magnetic measurements, carried out with VSM, SQUID, and AC susceptibility equipment, show formation of samples with single-domain grains as well as samples with multidomain grains. A large shift in superparamagnetic blocking temperature, below room temperature with increasing magnetic field, was also observed.
Journal of Superconductivity and Novel Magnetism, 2015
The powder of Ni 0.40 Zn 0.60 Fe 2 O 4 nanoparticles is synthesized using a microwave-assisted co... more The powder of Ni 0.40 Zn 0.60 Fe 2 O 4 nanoparticles is synthesized using a microwave-assisted combustion method. X-ray diffraction and IR spectrum analysis show that the sample has a single-phase spinel structure. Debye-Scherrer formula reveals a crystallize size of 49 nm ±5 %, whereas transmission electron microscopy (TEM) results show particle sizes in the range of 10 to 60 nm. Superparamagnetic nature of the sample was confirmed from a close hysteresis loop. The Curie temperature (T C) was found to be 422 • C and 30 K as a blocking temperature.
Journal of Magnetism and Magnetic Materials, 2015
Nanoparticle magnetic materials are suitable for multiple modern high end medical applications li... more Nanoparticle magnetic materials are suitable for multiple modern high end medical applications like targeted drug delivery, gene therapy, hyperthermia and MR thermometry imaging. Majority of these applications are confined to use of Mn-Zn ferrite nanoparticles. These nanoparticles are normally left in the body after their requisite application. Preparing these nanoparticles is usually a much involved job. However with the development of the simple technique Mn x Zn 1 À x Fe 2 O 4 nanoparticles could be prepared with much ease. The nanoparticles of Mn x Zn 1 À x Fe 2 O 4 with (x ¼1.0, 0.7, 0.5, 0.3, 0.0) were prepared and irradiated with gamma radiation of various intensities ranging between 500 R to 10,000 R, after appropriate structural and magnetic characterization. Irradiated samples were investigated for structural and magnetic properties, as well as for structural stability and cation distribution. The irradiated nanoparticles exhibited structural stability with varied cation distribution and magnetic properties, dependent on gamma radiation dose. Surprisingly samples also exhibited quenching of lattice parameter and particle size. The changes introduced in the cation distribution, lattice constant, particle size and magnetic properties were found to be irreversible with time lapse and were of permanent nature exhibiting good stability even after several months. Thus the useful properties of nanoparticles could be enhanced on modifying the cation distribution inside the nanoparticles by application of gamma radiation.
International Journal of Nanoscience, 2004
Nitrilotriacetate precursors have been used for synthesis of oxide materials. High permeability M... more Nitrilotriacetate precursors have been used for synthesis of oxide materials. High permeability Mn – Zn ferrite with general formula Mn x Zn 1-x Fe 2 O 4 where x=0.3/0.35/0.4/0.45/0.5/0.55/0.6/0.65/0.7 were prepared using this novel method. Formation of cubic spinel structure was confirmed by XRD, which also provided information on formation of fine particle material. The magnetic properties of these materials were investigated after sintering the same at 950°C, 1150°C, 1250°C and 1350°C in nitrogen atmosphere and at 1050°C in air and were found to be interesting.
International Journal of Nanotechnology, 2011
The amazing magnetic properties exhibited by nanoparticles Mn-Zn ferrites and their promising tec... more The amazing magnetic properties exhibited by nanoparticles Mn-Zn ferrites and their promising technological and medical applications have attracted much interest in recent years. Nanoparticle Mn x Zn (1-x) Fe 2 O 4 spinel ferrites with x = 0.6/0.63/0.65/0.67/0.7 were synthesised by the nitrilotriacetate precursor method employing microwave combustion synthesis. Powder X-ray diffractometry (XRD) confirmed the formation of the ferrite phase in all samples. IR analysis was done to verify formation of spinel structure. Elemental analysis using EDS confirmed the nanoparticle composition. The crystallite size was calculated from peak widths using the Scherrer formula, yielding a size in the range of 10-25 nm. Transmission electron microscopy was also performed on the samples to testify formation of nanosized crystallites in the sample. Saturation magnetisation (Mr), retentivity (Ms) and coercivity (Hc) measurements were carried out on the samples using standard hysteresis
ABSTRACT Nanoparticles Ni0.55Zn0.45Fe2O4 was synthesized at low temperature using novel precursor... more ABSTRACT Nanoparticles Ni0.55Zn0.45Fe2O4 was synthesized at low temperature using novel precursor method. The single spinel phase crystallization of sample was confirmed using XRD and IR spectra. Nanosize particles were confirmed using XRD and TEM images. Isomer shift in Mossbauer spectral studies are consistent with Fe ions in trivalent state. DC resistivity was of the order of 108 ohm cm that is two orders higher than those reported for NiZn ferrites prepared by conventional ceramic method. The high resistivity was attributed to nanosize particles, absence of Fe+2 ions and method of preparation.
International Journal of Thin Films Science and Technology, 2014
MnxZn1-xFe2O4 nanoparticles were chemically synthesized by co- precipitating metal ions in alkali... more MnxZn1-xFe2O4 nanoparticles were chemically synthesized by co- precipitating metal ions in alkaline aqueous solutions. The XRD peaks match up to spinel ferrites without any multi phase indication and clear visibility of ferrite FT-IR absorption bands confirm single phase spinal formation. Particle size derived from XRD data is authenticated by TEM micrographs. Thin films fabricated from this material on quartz substrate by pulse laser deposition were characterised using XRD. The XRD data revealed formation of spinel structure with a reasonable degree of texture. AFM analysis confirms nano granular film morphology with dimensions comparable to that of target grain. Magnetic data obtained from textured nanocrystalline Mn-Zn ferrite thin film measurements made known enhanced coercivity. The observed enhanced coercivity is explained with due consideration of film texture and surface disorder that originated from Mn concentration specific initial adsorption prior to nucleation, resulting in directional film growth.
Physica B: Condensed Matter, 2015
Nanoparticles of Mn 0.2 Zn 0.8 Fe 2 O 4 were chemically synthesized by co-precipitating the metal... more Nanoparticles of Mn 0.2 Zn 0.8 Fe 2 O 4 were chemically synthesized by co-precipitating the metal ions in aqueous solutions in a suitable alkaline medium. The identified XRD peaks confirm single phase spinal formation. The nanoparticle size authentication is carried out from XRD data using Debye Scherrer equation. Thin film fabricated from this nanomaterial by pulse laser deposition technique on quartz substrate was characterized using XRD and Raman spectroscopic techniques. XRD results revealed the formation of high degree of texture in the film. AFM analysis confirms nanogranular morphology and preferred directional growth. A high deposition pressure and the use of a laser plume confined to a small area for transportation of the target species created certain level of porosity in the deposited thin film. Magnetic property measurement of this highly textured nanocrystalline Mn-Zn ferrite thin film revealed enhancement in properties, which are explained on the basis of texture and surface features originated from film growth mechanism.
Nanoparticles of Ni0.45Zn0.55Fe2O 4 were chemically synthesized by novel precursor method at low ... more Nanoparticles of Ni0.45Zn0.55Fe2O 4 were chemically synthesized by novel precursor method at low temperature. Average particles size was found to be 37 nm. The Mössbauer spectroscopy studies were carried out on the sample for the investigation of magnetic and structural arrangement of Fe in the nano-crystalline ferrite samples. The values of isomer shift are consistent with Fe ions in trivalent