The U-type hexaferrites(Ba_(1−3x)La_(2x))4Co_(2)Fe_(36)O_(60)(x=0,0.05,0.10,0.15,0.20,0.25)have been synthesized by auto-combustion method.The work involves the study of structural,microstructural,dielectric,magnetic ...The U-type hexaferrites(Ba_(1−3x)La_(2x))4Co_(2)Fe_(36)O_(60)(x=0,0.05,0.10,0.15,0.20,0.25)have been synthesized by auto-combustion method.The work involves the study of structural,microstructural,dielectric,magnetic and magneto-dielectric properties of the prepared materials.The structural analysis has been done by X-ray diffraction technique along with Le Bail refinement which confirmed the pure hexagonal phase for all the samples.The microstructural analysis has been carried out by field-emission scanning electron microscopy.The vibrating sample magnetometer is used to measure the magnetic properties.The sample with a composition of x=0.15 has shown the maximum magnetization of approximately 73.31 emu/g with the remnant magnetization of 38.89 emu/g and coercive field of 1.77 kOe at room temperature.Moreover,the same sample has delivered the maximum mag-netodielectric response of about 54.18%at 1.5-T field.展开更多
This work promotes the room temperature energy storage properties of the multiferroics.In this approach,impacts of PrFeO_(3)doping on PT-based solid solutions(Pb1−xPrxTi1−xFexO_(3),x=0.21,0.22,0.23,0.24,0.25 and 0.26)...This work promotes the room temperature energy storage properties of the multiferroics.In this approach,impacts of PrFeO_(3)doping on PT-based solid solutions(Pb1−xPrxTi1−xFexO_(3),x=0.21,0.22,0.23,0.24,0.25 and 0.26)have been explored.X-ray diffraction(XRD)patterns were used to estimate the crystallographic parameters,confirming the single phase tetragonal structure.The ferroelectric Curie temperature(Tc FE)is observed to drop from 410 K to below room temperature as the Pr concentration increases.The ferroelectric P-E loops were used to determine the energy storage values at room temperature.The sample x=0.24 achieved the maximum value of energy storage density of 362.25 mJ/cm^(3)with the efficiency of 40.5%.The ferroelectric P-E loops were used to determine the energy storage values at room temperature.The validity of magnetoelectric coupling in all samples was confirmed by magneto-dielectric studies and found that the sample x=0.24 shows the maximum response with the coupling coefficient(γ)=15.54 g^(2)/emu^(2).展开更多
The perovskite(La_(0.7)Ba_(0.3))(Mn_(0.5)Fe_(0.5))_(1−x)Zr_(x)O_(3),where x=0.1,0.2 and 0.3,ceramics were synthesized by solid-state reaction method.The introductory structural studies were followed through by X-ray d...The perovskite(La_(0.7)Ba_(0.3))(Mn_(0.5)Fe_(0.5))_(1−x)Zr_(x)O_(3),where x=0.1,0.2 and 0.3,ceramics were synthesized by solid-state reaction method.The introductory structural studies were followed through by X-ray diffraction technique and the results have disclosed that all the samples were crystallized into an isolated phase.The Zr substitution in the resulting solid solutions increases the electrical conductivity and the maximum value of ac conductivity has been found to be~118.8 S.cm^(−1)for x=0.3 at 200°C(at 1 MHz).The frequency dependence of ac conductivity data follows Jonscher’s power law.The variation of the exponent n versus temperature follows the nonoverlapping small polaron tunneling(NSPT)model.The dielectric relaxation has been observed to be of non-Debye nature for all measuring temperatures(50-200°C).The impedance spectroscopy reveals that all the samples exhibit negative temperature coefficient of resistance(NTCR)behavior.The prepared samples(for x>1)are supposed to be suitable for cathode materials in SOFCs.展开更多
This work harmonizes the experimental and theoretical study of electrocaloric effect(ECE)in(Pb_(0.8)Bi_(0.2))(Zr_(0.52)Ti_(0.48))O_(3)solid solution by optimizing sintering temperature.Bi^(3+)-doped PbZr_(0.52)Ti_(0.4...This work harmonizes the experimental and theoretical study of electrocaloric effect(ECE)in(Pb_(0.8)Bi_(0.2))(Zr_(0.52)Ti_(0.48))O_(3)solid solution by optimizing sintering temperature.Bi^(3+)-doped PbZr_(0.52)Ti_(0.48)O_(3)solid solutions were synthesized by the conventional solid-state reaction method.Different samples were prepared by varying the sintering temperature.X-ray diffraction study con-firms the crystalline nature of all the samples.An immense value of polarization has been acquired in the optimized sample.The maximum adiabatic temperature change of order 2.53 K with electrocaloric strength of 1.26 K mm kV^(−1)has been achieved exper-imentally.Whereas a comparatively close value of ECE has been acquired from the theoretical calculations using a phenomeno-logical approach.Furthermore,a large value(218 mJ cm^(−3))of thermal energy conversion has been obtained using the Olsen cycle.展开更多
文摘The U-type hexaferrites(Ba_(1−3x)La_(2x))4Co_(2)Fe_(36)O_(60)(x=0,0.05,0.10,0.15,0.20,0.25)have been synthesized by auto-combustion method.The work involves the study of structural,microstructural,dielectric,magnetic and magneto-dielectric properties of the prepared materials.The structural analysis has been done by X-ray diffraction technique along with Le Bail refinement which confirmed the pure hexagonal phase for all the samples.The microstructural analysis has been carried out by field-emission scanning electron microscopy.The vibrating sample magnetometer is used to measure the magnetic properties.The sample with a composition of x=0.15 has shown the maximum magnetization of approximately 73.31 emu/g with the remnant magnetization of 38.89 emu/g and coercive field of 1.77 kOe at room temperature.Moreover,the same sample has delivered the maximum mag-netodielectric response of about 54.18%at 1.5-T field.
文摘This work promotes the room temperature energy storage properties of the multiferroics.In this approach,impacts of PrFeO_(3)doping on PT-based solid solutions(Pb1−xPrxTi1−xFexO_(3),x=0.21,0.22,0.23,0.24,0.25 and 0.26)have been explored.X-ray diffraction(XRD)patterns were used to estimate the crystallographic parameters,confirming the single phase tetragonal structure.The ferroelectric Curie temperature(Tc FE)is observed to drop from 410 K to below room temperature as the Pr concentration increases.The ferroelectric P-E loops were used to determine the energy storage values at room temperature.The sample x=0.24 achieved the maximum value of energy storage density of 362.25 mJ/cm^(3)with the efficiency of 40.5%.The ferroelectric P-E loops were used to determine the energy storage values at room temperature.The validity of magnetoelectric coupling in all samples was confirmed by magneto-dielectric studies and found that the sample x=0.24 shows the maximum response with the coupling coefficient(γ)=15.54 g^(2)/emu^(2).
文摘The perovskite(La_(0.7)Ba_(0.3))(Mn_(0.5)Fe_(0.5))_(1−x)Zr_(x)O_(3),where x=0.1,0.2 and 0.3,ceramics were synthesized by solid-state reaction method.The introductory structural studies were followed through by X-ray diffraction technique and the results have disclosed that all the samples were crystallized into an isolated phase.The Zr substitution in the resulting solid solutions increases the electrical conductivity and the maximum value of ac conductivity has been found to be~118.8 S.cm^(−1)for x=0.3 at 200°C(at 1 MHz).The frequency dependence of ac conductivity data follows Jonscher’s power law.The variation of the exponent n versus temperature follows the nonoverlapping small polaron tunneling(NSPT)model.The dielectric relaxation has been observed to be of non-Debye nature for all measuring temperatures(50-200°C).The impedance spectroscopy reveals that all the samples exhibit negative temperature coefficient of resistance(NTCR)behavior.The prepared samples(for x>1)are supposed to be suitable for cathode materials in SOFCs.
基金Author Shubhpreet Kaur also wishes to thank DEST SERB and Rusa-2.0 for providing financial support.
文摘This work harmonizes the experimental and theoretical study of electrocaloric effect(ECE)in(Pb_(0.8)Bi_(0.2))(Zr_(0.52)Ti_(0.48))O_(3)solid solution by optimizing sintering temperature.Bi^(3+)-doped PbZr_(0.52)Ti_(0.48)O_(3)solid solutions were synthesized by the conventional solid-state reaction method.Different samples were prepared by varying the sintering temperature.X-ray diffraction study con-firms the crystalline nature of all the samples.An immense value of polarization has been acquired in the optimized sample.The maximum adiabatic temperature change of order 2.53 K with electrocaloric strength of 1.26 K mm kV^(−1)has been achieved exper-imentally.Whereas a comparatively close value of ECE has been acquired from the theoretical calculations using a phenomeno-logical approach.Furthermore,a large value(218 mJ cm^(−3))of thermal energy conversion has been obtained using the Olsen cycle.
