Marian Kubliha | Slovak University of Technology (original) (raw)

Papers by Marian Kubliha

Acta Mechatronica, Mar 31, 2020

The paper describes the measurements of modulus of elasticity of thin samples and related Poisson... more The paper describes the measurements of modulus of elasticity of thin samples and related Poisson number by one device-Searle´s pendulum. We have focused our attention mainly to non-traditional samples with non-standard (i.e. other than circular) cross-sections.

Russian Journal of Electrochemistry, Jun 1, 2019

The vitreous system GeS2–Ga2S3 can incorporate a large amount of alkali salts, for example NaI, a... more The vitreous system GeS2–Ga2S3 can incorporate a large amount of alkali salts, for example NaI, and such materials have a potential to be used as solid electrolytes for all-solid-state batteries. The present work focuses on the effects of NaI addition in the (GeS2)x(Ga2S3)100 –x glass matrix, where x = 65, 72, 80, and 88. AC and DC electrical and dielectric properties were measured in the temperature range from 20 up to 200°C and in the frequency range 1 Hz–100 kHz, in air, at different temperatures by steps of 1°C. The values of electrical conductivity significantly increase with increasing of NaI content. The DC conductivity values 2.5 × 10–4 S m–1 at room temperature were detected for glasses with 25 and 30 mol % of NaI in (GeS2)72(Ga2S3)28 and with 30 mol % NaI in (GeS2)65(Ga2S3)35 matrices. Samples with NaI concentration higher than 20 mol % show a poor stability against moisture. In order to improve their stability the glass composition was modified by addition of 2.5 mol % P2S5 in the system. The activation energy values slightly decrease with NaI content. The GeS2/Ga2S3 ratio and P2S5 addition to the glass matrix have low effect on transport properties. The DC conductivity, electrical relaxation, and depolarization mechanisms are similar. Electrical charge transfer is connected with hopping of Na+ ions or reorientation of dipoles containing these ions.

Defect and Diffusion Forum, Apr 1, 2012

ABSTRACT The paper is devoted to the study of thermal, as well as mechanical properties of polyur... more ABSTRACT The paper is devoted to the study of thermal, as well as mechanical properties of polyurethane samples (PU) filled by carbon black (CB), graphite (G) and MWCNT(CNT). Thermal conductivity k(W.m-1.K-1), specific heat capacity cp(J.kg-1.K-1) and thermal diffusivity a(mm2.s-1) were measured by the impulse method. An increase of all the above mentioned thermal parameters after addition of fillers under investigation was observed. The dc electrical conductivity drastically increases from PUPU+CBPU+GPU+CNT.

Nucleation and Atmospheric Aerosols, 2020

Correlation between local values of dielectric permittivity and electric potential in axially sym... more Correlation between local values of dielectric permittivity and electric potential in axially symmetric dielectric medium located into a constant external electric field was analyzed perpendicularly to the axis of symmetry. The simple experimental method for identification of dielectric profile of materials with mentioned symmetry was suggested on the basis of this correlation. Then the qualitative assessment of the technological texture of a ceramic blank designed for the production of very high voltage (VHV) insulators was done. Measured voltage differences on the surface of sample of the ceramic blank placed between two electrodes and connected to a source of constant electrical voltage was measured. The technological texture was evaluated in the form of a flat map of curves with the same values of mentioned voltage differences.

Journal of Non-crystalline Solids, Oct 1, 2013

ABSTRACT Bulk glasses Ge250Ga17As83S650 were prepared by direct synthesis from high purity (6 N) ... more ABSTRACT Bulk glasses Ge250Ga17As83S650 were prepared by direct synthesis from high purity (6 N) elements S, Ga, Ge, As and doped by rare earth (RE) elements — Pr, Dy, Nd, Sm or Ho. The DC and AC electrical conductivity were measured, and activation energies of relevant conductivity process were obtained from Arrhenius plots of its temperature dependence. The real part of complex permittivity as a function of temperature and frequency was deduced from AC conductivity data. Room temperature optical transmission and low temperature photoluminescence (PL) spectra were further investigated. The major feature in low-temperature PL spectra is the presence of the broad band luminescence of the base glass and relatively sharp 4f–4f radiative transitions due to the presence of RE3+ ions. When the broad band luminescence spectrally overlaps with 4f–4f transitions of RE3+ ions we can, in some cases, also observe the direct evidence of the energy transfer between the host glass and respective RE dopants which is manifested by the re-absorption of the base glass luminescence due to 4f–4f up-transitions.

Ceramics International, Apr 1, 2023

Edukacja-Technika-Informatyka, 2015

Journal of Non-crystalline Solids, Oct 1, 2009

Chalcogenide bulk glasses Ge 20 Se 80Àx Te x for xe(0,15) have been prepared by systematic replac... more Chalcogenide bulk glasses Ge 20 Se 80Àx Te x for xe(0,15) have been prepared by systematic replacement of Se by Te. Selected glasses have been doped with Ho, Er and Pr, and samples have been characterized by transmission spectroscopy, measurements of dc electrical conductivity and low-temperature photoluminescence. Absorption coefficients have been derived from measured transmittance and estimated reflectance. Arrhenius plots of dc electrical conductivity, in the measured temperature range 300-460 K, are characterized by single activation energies roughly equal to the half of the optical gap. Activation energies deduced from Arrhenius plots reveal a systematic decrease with increasing Te content. Similarly, both absorption and low-temperature photoluminescence spectra reveal shifts of absorption edge and/ or dominant luminescence band to longer wavelength due to Te ? Se substitution. Samples doped with Ho and Er exhibit a strong luminescence at 1200 and 1540 nm due to 5 I 6 ? 5 I 8 and 4 I 13/2 ? 4 I 15/2 transitions of Ho 3+ and Er 3+ ions, respectively. Pr doped samples exhibit only a relatively weak luminescence peak at 1590 nm, which we tentatively assign to 3 F 3 ? 3 H 4 transition of Pr 3+ ions. Absorption of the base glass luminescence at 1460 and 1520 nm has been observed at low temperature on samples doped with Pr and Er, respectively.

Russian Journal of Electrochemistry, 2021

The non-linear response of various physical properties of glasses on mixing of alkali ions is a w... more The non-linear response of various physical properties of glasses on mixing of alkali ions is a well-known anomaly in materials science. In this paper, the mixed alkali effect in antimony oxide based glasses with composition 60Sb2O3–20WO3–(20 – x)Li2O–x(M2O), where x = 0, 5, 10, 15, 20 (in mol %) and M = Na or K, is studied. The influence of Na/Li and K/Li ratios on ionic AC and DC conductivities is studied. Temperature dependences of the DC conductivity obey Arrhenius-like relation. The conductivity steeply decreases with increasing Na or K content due to larger ionic radius of Na or K ions compared to that of Li. The relation between composition and local movement of electrical charge was investigated and quantified using the measurement of thermally stimulated depolarization currents. The artificial neural network methods for optimizing experimental parameters used in this paper represent a new approach in comparison with works done on glasses with similar composition. The prepared numerical model could be used for the description of the influence of polarization parameters and the optimization of further measurements oriented on activation energies of ion polarization related to local transport of electrical charge, i.e. Li+ and Na+ ions in our case.

Russian Journal of Electrochemistry, 2021

Electrical and dielectric properties of ternary glasses in the Sb2O3–PbCl2–AgCl system were inves... more Electrical and dielectric properties of ternary glasses in the Sb2O3–PbCl2–AgCl system were investigated across a broad temperature and frequency range. The studied glass system is interesting since it possesses a high ionic conductivity. The (Sb2O3)x–(PbCl2)100 –y–x–(AgCl)y glasses were prepared by melt-quenching method from high purity components. Different batches of these glasses were investigated with varying molar content of both Sb2O3 (45 ≤ x ≤ 70 mol %) and AgCl (5 ≤ y ≤ 25 mol %). The colour of the prepared chloro-antimonite glasses varies between yellow and brown. The glass transition temperature (Tg) decreases with increasing AgCl concentrations. DC and AC electrical conductivities and complex electrical modulus were measured across a temperature range from room temperature up to 200°C and across a frequency range between 0.2 and 105 Hz. The dependence of DC conductivity on temperature follows the so-called Arrhenius-like equation. The DC conductivity at constant temperature significantly increases with increasing AgCl or PbCl2 content. It was found that the activation energy of conduction process decreases with the substitution of PbCl2 by AgCl from 1 eV down to 0.56 eV for (Sb2O3)50-(PbCl2)45–(AgCl)5 and (Sb2O3)50–(PbCl2)25–(AgCl)25, respectively. The influence of the composition on the AC conductivity of the investigated glasses is also discussed.

Materials Science Forum, 2020

New technologies are using natural fibres in composites materials in the industry. It is still of... more New technologies are using natural fibres in composites materials in the industry. It is still often natural fibres in modern buildings, chemists, airports, sport and automotive. Using for construction pieces and their better properties than steel or traditional materials. New forward science and technic are recycled or decrease waste. The problem for central Europe is a waste of agricultural, invention relates to an epoxy resin filled with an organo-inorganic filler of natural origin, production especially plants and sheep wool as well as other usable wastes such as old textiles. New applications are in new construction types and industries finding cheaper materials. There is available modern technology for injection moulding granulate polypropylene with filler from sheep wool and plant fibres. For example, to make furniture or building cladding. This could reduce waste production, pollution of nature and emissions in the production of these products from new raw materials. The wor...

Russian Journal of Electrochemistry, 2019

The mixed alkaline effect (MAE) is a well-known anomaly in glasses. It results in a non-linear re... more The mixed alkaline effect (MAE) is a well-known anomaly in glasses. It results in a non-linear response of various physical properties on mixing of alkali ions in the glass. In this paper, the MAE is studied in antimony oxides based glasses 60Sb 2 O 3-20MoO 3-(20-x)Li 2 O-xNa 2 O and 60Sb 2 O 3-20MoO 3-(20x)Li 2 O-xK 2 O (in mol %). The influence of Na/Li and K/Li ratios on ionic AC and DC conductivities, and T g is presented. Dependences of T g on x, in both types of glasses, have typical minima at x ≅ 10, it means that the minima take place at approximately equal concentrations of both mixed alkali ions. The minimum for K 2 O containing glasses is deeper, probably due to a larger difference between ionic radii of K + and Li + ions. In glasses with one type of alkali ion, T g decreases in the sequence: K → Li → Na. Temperature dependences of the DC conductivity obey Arrhenius-like relation. The conductivity steeply decreases with increasing Na or K content due to the larger ionic radius of both ions comparing to that of Li ions. At the same time, the conduction activation energy goes through a flat maximum at x = 15 (1.21 eV) for Na 2 O modifier and at x = 5 (1.16 eV), for K 2 O modifier. In antimony oxide based glasses, Li + , Na + , and K + ions are modifiers and dominant charge-carriers. Due to larger ionic radii of Na + , and K + , the decrease of the conductivity after their addition is reasonable.

Materials Science Forum, 2019

The paper deals with the modeling of the technological texture of the pressed ceramic materials i... more The paper deals with the modeling of the technological texture of the pressed ceramic materials in the radial and axial direction, which consists in the graphical representation and subsequent analysis of the distribution of the electrostatic field potential differences on the surface of the dielectric sample with the diameter d and the thickness h located between the electrodes. In occasion of observing radial texture the electrodes have the cylindrical configuration and in occasion of observing the axial texture in the sample the electrodes have the axial configuration. The theoretical relationship in the paper is derived for the calculation of the voltage values measured at any position between the center electrode and the peripheral electrode, at a constant voltage U applied to the outer and inner electrodes of the dielectric sample of thickness h of the raw ceramic sample material (radial texture). Measurements have demonstrated the suitability of identifying the technological ...

Journal of Non-Crystalline Solids, 2018

The glass-forming domain in the new Sb 2 O 3-PbCl 2-LiCl system has been delimited. Systematic in... more The glass-forming domain in the new Sb 2 O 3-PbCl 2-LiCl system has been delimited. Systematic investigations were undertaken to establish the influence of each starting component on the characteristic temperatures (T g and T x) and the density. Glasses have T g between approximately 255°C and 310°C for the richest LiCl and the free LiCl compositions, respectively. A decrease of the network connectivity due to the PbCl 2 or LiCl is supported by the data. AC, DC, and Thermally Simulated Deposition Current (TSDC) measurements were carried out to study the electrical properties of the lithium and lead chloride antimonate glasses. The interpretation of the results was supplemented by X-ray diffraction and TEM measurements in order to identify and quantify the crystalline phases observed in crystallized compositions after quenching. The positive effect of PbCl 2 on conductivity was established although the TSDC demonstrates the Li + ions can be considered as the only charge carriers in this system.

AIP Conference Proceedings, 2016

The exponential increase of the absorption coefficient near the absorption edge is usually explai... more The exponential increase of the absorption coefficient near the absorption edge is usually explained by existence of the density-of-states tails. Among the quoted theoretical models which are widely used to explain the manifestations of the Urbach rule in semiconductors, are the Sumi–Toyozava and the Dow–Redfield models and ab initio (from begining) theory. Our barrier-cluster-heating model assumes the different creating mechanism of exponential tails. The energy by optical transition is provided to electrons except from photons also from vibration of microregion. It deals about the replenishment of absented photons energy, which is smaller as gap width. Absented energy needed for the transition by light absorption is acumulated in certain microregions of material in the form of vibrational energy. At absorption sufficiently big package of accumulated energy can be used. Energy of emptied microarea is filled by phonons from surrounding of microarea (as result of temperature status of surrounding), resp. p...

Journal of Thermal Analysis and Calorimetry, 2015

The temperature dependencies of the direct current (DC) conductivity of illitic clay, which conta... more The temperature dependencies of the direct current (DC) conductivity of illitic clay, which contained 86 % of illite of 1 M polytype, were measured in a temperature range of 20-450°C, on green samples and on the samples after thermal treatments at 400-1200°C. The release of the physically bound water from a green sample takes place in three stages-at 72, 186 and 298°C. After heating at 400°C, the movement of dominant H ? and OHions is characterized by the conduction activation energy (CAE) of 0.31 ± 0.02 eV, below 220°C. At higher temperatures, K ? ions are dominant charge carriers with a CAE of 1.12 ± 0.02 eV. Upon heating at 450°C, the DC conductivity slightly increases; a slightly higher CAE (1.22 eV) indicates that K ? ions are moving in a more disordered structure, probably due to starting dehydroxylation. Significant structural changes, which influence the DC conductivity, are finished at 550°C. After preheating from 550 up to 1000°C, the defect structure, type, concentration, and mobility of charge carriers are not significantly changed as the temperature dependence of the DC conductivity is independent of the temperature of firing. During preheating at 1100°C, vitrification and sintering are almost completed. The high mobility of K ? ions in the glassy phase results in a high DC conductivity with the CAE equal to 0.76 eV.

Physics and Simulation of Optoelectronic Devices XXVIII, 2020

Journal of Electronic Materials, 2019

Electrical properties of amorphous Ag0.5(As40S30Se30)99.5 alloy have been investigated using comp... more Electrical properties of amorphous Ag0.5(As40S30Se30)99.5 alloy have been investigated using complex impedance spectroscopy at different temperatures in the frequency range from 100 Hz to 1 MHz. Direct current (DC) conductivity data follows Arrhenius behavior, while the nature of frequency dependence of alternating current (AC) conductivity follows Jonscher’s power law. Impedance spectra were analyzed by means of an equivalent-circuit model that revealed the presence of a temperature-dependent electrical relaxation phenomenon of the non-Debye type. Different activation energy values of conduction and of the relaxation process were obtained, suggesting different mechanisms of conduction and relaxation. Dielectric properties were analyzed where the real part (ε′) and imaginary part (ε″) of the dielectric constant were found to decrease with frequency and increase with temperature. The temperature coefficient of dielectric constant (TCP) is evaluated. The analysis of dielectric loss leads to determination of the barrier height Wm which is found to be 0.086 eV.

The problem of the reconstruction of the historical building surface layers is in material compat... more The problem of the reconstruction of the historical building surface layers is in material compatibility. The crucial physical properties of the convenient material structureon reconstruction are moisture and temperature induced deformations. This paper presents experimental results of the coupled moisture and temperature induced expansionof innovative plaster. Detailed thermodynamic analysis can show the deformation contributions of moisture and temperature respectively.The measurements are performedfor moisture content from the dry state to the saturation water contentand temperature range of 10 - 40°C.

Acta Mechatronica, Mar 31, 2020

The paper describes the measurements of modulus of elasticity of thin samples and related Poisson... more The paper describes the measurements of modulus of elasticity of thin samples and related Poisson number by one device-Searle´s pendulum. We have focused our attention mainly to non-traditional samples with non-standard (i.e. other than circular) cross-sections.

Russian Journal of Electrochemistry, Jun 1, 2019

The vitreous system GeS2–Ga2S3 can incorporate a large amount of alkali salts, for example NaI, a... more The vitreous system GeS2–Ga2S3 can incorporate a large amount of alkali salts, for example NaI, and such materials have a potential to be used as solid electrolytes for all-solid-state batteries. The present work focuses on the effects of NaI addition in the (GeS2)x(Ga2S3)100 –x glass matrix, where x = 65, 72, 80, and 88. AC and DC electrical and dielectric properties were measured in the temperature range from 20 up to 200°C and in the frequency range 1 Hz–100 kHz, in air, at different temperatures by steps of 1°C. The values of electrical conductivity significantly increase with increasing of NaI content. The DC conductivity values 2.5 × 10–4 S m–1 at room temperature were detected for glasses with 25 and 30 mol % of NaI in (GeS2)72(Ga2S3)28 and with 30 mol % NaI in (GeS2)65(Ga2S3)35 matrices. Samples with NaI concentration higher than 20 mol % show a poor stability against moisture. In order to improve their stability the glass composition was modified by addition of 2.5 mol % P2S5 in the system. The activation energy values slightly decrease with NaI content. The GeS2/Ga2S3 ratio and P2S5 addition to the glass matrix have low effect on transport properties. The DC conductivity, electrical relaxation, and depolarization mechanisms are similar. Electrical charge transfer is connected with hopping of Na+ ions or reorientation of dipoles containing these ions.

Defect and Diffusion Forum, Apr 1, 2012

ABSTRACT The paper is devoted to the study of thermal, as well as mechanical properties of polyur... more ABSTRACT The paper is devoted to the study of thermal, as well as mechanical properties of polyurethane samples (PU) filled by carbon black (CB), graphite (G) and MWCNT(CNT). Thermal conductivity k(W.m-1.K-1), specific heat capacity cp(J.kg-1.K-1) and thermal diffusivity a(mm2.s-1) were measured by the impulse method. An increase of all the above mentioned thermal parameters after addition of fillers under investigation was observed. The dc electrical conductivity drastically increases from PUPU+CBPU+GPU+CNT.

Nucleation and Atmospheric Aerosols, 2020

Correlation between local values of dielectric permittivity and electric potential in axially sym... more Correlation between local values of dielectric permittivity and electric potential in axially symmetric dielectric medium located into a constant external electric field was analyzed perpendicularly to the axis of symmetry. The simple experimental method for identification of dielectric profile of materials with mentioned symmetry was suggested on the basis of this correlation. Then the qualitative assessment of the technological texture of a ceramic blank designed for the production of very high voltage (VHV) insulators was done. Measured voltage differences on the surface of sample of the ceramic blank placed between two electrodes and connected to a source of constant electrical voltage was measured. The technological texture was evaluated in the form of a flat map of curves with the same values of mentioned voltage differences.

Journal of Non-crystalline Solids, Oct 1, 2013

ABSTRACT Bulk glasses Ge250Ga17As83S650 were prepared by direct synthesis from high purity (6 N) ... more ABSTRACT Bulk glasses Ge250Ga17As83S650 were prepared by direct synthesis from high purity (6 N) elements S, Ga, Ge, As and doped by rare earth (RE) elements — Pr, Dy, Nd, Sm or Ho. The DC and AC electrical conductivity were measured, and activation energies of relevant conductivity process were obtained from Arrhenius plots of its temperature dependence. The real part of complex permittivity as a function of temperature and frequency was deduced from AC conductivity data. Room temperature optical transmission and low temperature photoluminescence (PL) spectra were further investigated. The major feature in low-temperature PL spectra is the presence of the broad band luminescence of the base glass and relatively sharp 4f–4f radiative transitions due to the presence of RE3+ ions. When the broad band luminescence spectrally overlaps with 4f–4f transitions of RE3+ ions we can, in some cases, also observe the direct evidence of the energy transfer between the host glass and respective RE dopants which is manifested by the re-absorption of the base glass luminescence due to 4f–4f up-transitions.

Ceramics International, Apr 1, 2023

Edukacja-Technika-Informatyka, 2015

Journal of Non-crystalline Solids, Oct 1, 2009

Chalcogenide bulk glasses Ge 20 Se 80Àx Te x for xe(0,15) have been prepared by systematic replac... more Chalcogenide bulk glasses Ge 20 Se 80Àx Te x for xe(0,15) have been prepared by systematic replacement of Se by Te. Selected glasses have been doped with Ho, Er and Pr, and samples have been characterized by transmission spectroscopy, measurements of dc electrical conductivity and low-temperature photoluminescence. Absorption coefficients have been derived from measured transmittance and estimated reflectance. Arrhenius plots of dc electrical conductivity, in the measured temperature range 300-460 K, are characterized by single activation energies roughly equal to the half of the optical gap. Activation energies deduced from Arrhenius plots reveal a systematic decrease with increasing Te content. Similarly, both absorption and low-temperature photoluminescence spectra reveal shifts of absorption edge and/ or dominant luminescence band to longer wavelength due to Te ? Se substitution. Samples doped with Ho and Er exhibit a strong luminescence at 1200 and 1540 nm due to 5 I 6 ? 5 I 8 and 4 I 13/2 ? 4 I 15/2 transitions of Ho 3+ and Er 3+ ions, respectively. Pr doped samples exhibit only a relatively weak luminescence peak at 1590 nm, which we tentatively assign to 3 F 3 ? 3 H 4 transition of Pr 3+ ions. Absorption of the base glass luminescence at 1460 and 1520 nm has been observed at low temperature on samples doped with Pr and Er, respectively.

Russian Journal of Electrochemistry, 2021

The non-linear response of various physical properties of glasses on mixing of alkali ions is a w... more The non-linear response of various physical properties of glasses on mixing of alkali ions is a well-known anomaly in materials science. In this paper, the mixed alkali effect in antimony oxide based glasses with composition 60Sb2O3–20WO3–(20 – x)Li2O–x(M2O), where x = 0, 5, 10, 15, 20 (in mol %) and M = Na or K, is studied. The influence of Na/Li and K/Li ratios on ionic AC and DC conductivities is studied. Temperature dependences of the DC conductivity obey Arrhenius-like relation. The conductivity steeply decreases with increasing Na or K content due to larger ionic radius of Na or K ions compared to that of Li. The relation between composition and local movement of electrical charge was investigated and quantified using the measurement of thermally stimulated depolarization currents. The artificial neural network methods for optimizing experimental parameters used in this paper represent a new approach in comparison with works done on glasses with similar composition. The prepared numerical model could be used for the description of the influence of polarization parameters and the optimization of further measurements oriented on activation energies of ion polarization related to local transport of electrical charge, i.e. Li+ and Na+ ions in our case.

Russian Journal of Electrochemistry, 2021

Electrical and dielectric properties of ternary glasses in the Sb2O3–PbCl2–AgCl system were inves... more Electrical and dielectric properties of ternary glasses in the Sb2O3–PbCl2–AgCl system were investigated across a broad temperature and frequency range. The studied glass system is interesting since it possesses a high ionic conductivity. The (Sb2O3)x–(PbCl2)100 –y–x–(AgCl)y glasses were prepared by melt-quenching method from high purity components. Different batches of these glasses were investigated with varying molar content of both Sb2O3 (45 ≤ x ≤ 70 mol %) and AgCl (5 ≤ y ≤ 25 mol %). The colour of the prepared chloro-antimonite glasses varies between yellow and brown. The glass transition temperature (Tg) decreases with increasing AgCl concentrations. DC and AC electrical conductivities and complex electrical modulus were measured across a temperature range from room temperature up to 200°C and across a frequency range between 0.2 and 105 Hz. The dependence of DC conductivity on temperature follows the so-called Arrhenius-like equation. The DC conductivity at constant temperature significantly increases with increasing AgCl or PbCl2 content. It was found that the activation energy of conduction process decreases with the substitution of PbCl2 by AgCl from 1 eV down to 0.56 eV for (Sb2O3)50-(PbCl2)45–(AgCl)5 and (Sb2O3)50–(PbCl2)25–(AgCl)25, respectively. The influence of the composition on the AC conductivity of the investigated glasses is also discussed.

Materials Science Forum, 2020

New technologies are using natural fibres in composites materials in the industry. It is still of... more New technologies are using natural fibres in composites materials in the industry. It is still often natural fibres in modern buildings, chemists, airports, sport and automotive. Using for construction pieces and their better properties than steel or traditional materials. New forward science and technic are recycled or decrease waste. The problem for central Europe is a waste of agricultural, invention relates to an epoxy resin filled with an organo-inorganic filler of natural origin, production especially plants and sheep wool as well as other usable wastes such as old textiles. New applications are in new construction types and industries finding cheaper materials. There is available modern technology for injection moulding granulate polypropylene with filler from sheep wool and plant fibres. For example, to make furniture or building cladding. This could reduce waste production, pollution of nature and emissions in the production of these products from new raw materials. The wor...

Russian Journal of Electrochemistry, 2019

The mixed alkaline effect (MAE) is a well-known anomaly in glasses. It results in a non-linear re... more The mixed alkaline effect (MAE) is a well-known anomaly in glasses. It results in a non-linear response of various physical properties on mixing of alkali ions in the glass. In this paper, the MAE is studied in antimony oxides based glasses 60Sb 2 O 3-20MoO 3-(20-x)Li 2 O-xNa 2 O and 60Sb 2 O 3-20MoO 3-(20x)Li 2 O-xK 2 O (in mol %). The influence of Na/Li and K/Li ratios on ionic AC and DC conductivities, and T g is presented. Dependences of T g on x, in both types of glasses, have typical minima at x ≅ 10, it means that the minima take place at approximately equal concentrations of both mixed alkali ions. The minimum for K 2 O containing glasses is deeper, probably due to a larger difference between ionic radii of K + and Li + ions. In glasses with one type of alkali ion, T g decreases in the sequence: K → Li → Na. Temperature dependences of the DC conductivity obey Arrhenius-like relation. The conductivity steeply decreases with increasing Na or K content due to the larger ionic radius of both ions comparing to that of Li ions. At the same time, the conduction activation energy goes through a flat maximum at x = 15 (1.21 eV) for Na 2 O modifier and at x = 5 (1.16 eV), for K 2 O modifier. In antimony oxide based glasses, Li + , Na + , and K + ions are modifiers and dominant charge-carriers. Due to larger ionic radii of Na + , and K + , the decrease of the conductivity after their addition is reasonable.

Materials Science Forum, 2019

The paper deals with the modeling of the technological texture of the pressed ceramic materials i... more The paper deals with the modeling of the technological texture of the pressed ceramic materials in the radial and axial direction, which consists in the graphical representation and subsequent analysis of the distribution of the electrostatic field potential differences on the surface of the dielectric sample with the diameter d and the thickness h located between the electrodes. In occasion of observing radial texture the electrodes have the cylindrical configuration and in occasion of observing the axial texture in the sample the electrodes have the axial configuration. The theoretical relationship in the paper is derived for the calculation of the voltage values measured at any position between the center electrode and the peripheral electrode, at a constant voltage U applied to the outer and inner electrodes of the dielectric sample of thickness h of the raw ceramic sample material (radial texture). Measurements have demonstrated the suitability of identifying the technological ...

Journal of Non-Crystalline Solids, 2018

The glass-forming domain in the new Sb 2 O 3-PbCl 2-LiCl system has been delimited. Systematic in... more The glass-forming domain in the new Sb 2 O 3-PbCl 2-LiCl system has been delimited. Systematic investigations were undertaken to establish the influence of each starting component on the characteristic temperatures (T g and T x) and the density. Glasses have T g between approximately 255°C and 310°C for the richest LiCl and the free LiCl compositions, respectively. A decrease of the network connectivity due to the PbCl 2 or LiCl is supported by the data. AC, DC, and Thermally Simulated Deposition Current (TSDC) measurements were carried out to study the electrical properties of the lithium and lead chloride antimonate glasses. The interpretation of the results was supplemented by X-ray diffraction and TEM measurements in order to identify and quantify the crystalline phases observed in crystallized compositions after quenching. The positive effect of PbCl 2 on conductivity was established although the TSDC demonstrates the Li + ions can be considered as the only charge carriers in this system.

AIP Conference Proceedings, 2016

The exponential increase of the absorption coefficient near the absorption edge is usually explai... more The exponential increase of the absorption coefficient near the absorption edge is usually explained by existence of the density-of-states tails. Among the quoted theoretical models which are widely used to explain the manifestations of the Urbach rule in semiconductors, are the Sumi–Toyozava and the Dow–Redfield models and ab initio (from begining) theory. Our barrier-cluster-heating model assumes the different creating mechanism of exponential tails. The energy by optical transition is provided to electrons except from photons also from vibration of microregion. It deals about the replenishment of absented photons energy, which is smaller as gap width. Absented energy needed for the transition by light absorption is acumulated in certain microregions of material in the form of vibrational energy. At absorption sufficiently big package of accumulated energy can be used. Energy of emptied microarea is filled by phonons from surrounding of microarea (as result of temperature status of surrounding), resp. p...

Journal of Thermal Analysis and Calorimetry, 2015

The temperature dependencies of the direct current (DC) conductivity of illitic clay, which conta... more The temperature dependencies of the direct current (DC) conductivity of illitic clay, which contained 86 % of illite of 1 M polytype, were measured in a temperature range of 20-450°C, on green samples and on the samples after thermal treatments at 400-1200°C. The release of the physically bound water from a green sample takes place in three stages-at 72, 186 and 298°C. After heating at 400°C, the movement of dominant H ? and OHions is characterized by the conduction activation energy (CAE) of 0.31 ± 0.02 eV, below 220°C. At higher temperatures, K ? ions are dominant charge carriers with a CAE of 1.12 ± 0.02 eV. Upon heating at 450°C, the DC conductivity slightly increases; a slightly higher CAE (1.22 eV) indicates that K ? ions are moving in a more disordered structure, probably due to starting dehydroxylation. Significant structural changes, which influence the DC conductivity, are finished at 550°C. After preheating from 550 up to 1000°C, the defect structure, type, concentration, and mobility of charge carriers are not significantly changed as the temperature dependence of the DC conductivity is independent of the temperature of firing. During preheating at 1100°C, vitrification and sintering are almost completed. The high mobility of K ? ions in the glassy phase results in a high DC conductivity with the CAE equal to 0.76 eV.

Physics and Simulation of Optoelectronic Devices XXVIII, 2020

Journal of Electronic Materials, 2019

Electrical properties of amorphous Ag0.5(As40S30Se30)99.5 alloy have been investigated using comp... more Electrical properties of amorphous Ag0.5(As40S30Se30)99.5 alloy have been investigated using complex impedance spectroscopy at different temperatures in the frequency range from 100 Hz to 1 MHz. Direct current (DC) conductivity data follows Arrhenius behavior, while the nature of frequency dependence of alternating current (AC) conductivity follows Jonscher’s power law. Impedance spectra were analyzed by means of an equivalent-circuit model that revealed the presence of a temperature-dependent electrical relaxation phenomenon of the non-Debye type. Different activation energy values of conduction and of the relaxation process were obtained, suggesting different mechanisms of conduction and relaxation. Dielectric properties were analyzed where the real part (ε′) and imaginary part (ε″) of the dielectric constant were found to decrease with frequency and increase with temperature. The temperature coefficient of dielectric constant (TCP) is evaluated. The analysis of dielectric loss leads to determination of the barrier height Wm which is found to be 0.086 eV.

The problem of the reconstruction of the historical building surface layers is in material compat... more The problem of the reconstruction of the historical building surface layers is in material compatibility. The crucial physical properties of the convenient material structureon reconstruction are moisture and temperature induced deformations. This paper presents experimental results of the coupled moisture and temperature induced expansionof innovative plaster. Detailed thermodynamic analysis can show the deformation contributions of moisture and temperature respectively.The measurements are performedfor moisture content from the dry state to the saturation water contentand temperature range of 10 - 40°C.