The main focus of the research was to correlate the microstructure with dielectric and magnetic properties of Bi1-xBaxFeO3 samples. Bi1-xBaxFeO3 samples（x = 0.1, 0.2 and 0.3） were synthesized by the conventional sol...The main focus of the research was to correlate the microstructure with dielectric and magnetic properties of Bi1-xBaxFeO3 samples. Bi1-xBaxFeO3 samples（x = 0.1, 0.2 and 0.3） were synthesized by the conventional solid-state reaction method using nano-powders of Bi2O3, Fe2O3, and BaCO3. Thereafter, field emission scanning electron microscope and X-ray diffraction（XRD） techniques were used to examine the structure and phase of the samples. Phase analysis by XRD indicated that the single-phase perovskite structure was formed with possible increment in lattice parameter with increasing Ba doping. Complex permeability（u＇iand u＇＇i） measured using impedance analyzer confirmed the increase in magnetic property with increasing Ba doping. Finally, dielectric constant（k） was analyzed as a function of temperature at different frequencies. Dielectric constant as high as 2900 was attained in this research for Bi0.8Ba0.2FeO3 sample due to reduction in leakage current at this composition.展开更多
Frequency-dependent dielectric constant,dielectric loss,AC conductivity values and complex impedance spectra of V_(2)O_(5)-added Ni-Co-Zn ferrites(Ni_(0.62)Co_(0.03)Zn_(0.35)Fe_(2)O_(4)+xV_(2)O_(5),where x=0,0.5,1 and...Frequency-dependent dielectric constant,dielectric loss,AC conductivity values and complex impedance spectra of V_(2)O_(5)-added Ni-Co-Zn ferrites(Ni_(0.62)Co_(0.03)Zn_(0.35)Fe_(2)O_(4)+xV_(2)O_(5),where x=0,0.5,1 and 1.5 wt.%)have been investigated at room tempera-ture.The dielectric properties of the samples follow the Maxwell-Wagner polarization model.An inverse relationship was found between dielectric constant and AC electrical resistivity for all the samples.The dielectric constants decreased with the addition of V_(2)O_(5),while the electrical resistivities of V_(2)O_(5)-added Ni-Co-Zn ferrites are found to be larger than that of pure Ni-Co-Zn ferrite.The AC conductivity was reduced with the addition of V_(2)O_(5)to Ni-Co-Zn ferrite at lower-frequency region.However,AC conductivity shows a sharp increase at higher-frequency region,which could be attributed to the enhancement of electron hopping between the Fe2+and Fe3+ions in the ferrite matrix due to the activity of the grains.The complex impedance spectroscopy results through Cole-Cole/Nyquist plot have demonstrated a single semicircular arc.It indicates that conduction mechanism takes place predominantly through the grain/bulk property,which could be ascribed to the larger grain size of V_(2)O_(5)-added Ni-Co-Zn ferrites.展开更多
文摘The main focus of the research was to correlate the microstructure with dielectric and magnetic properties of Bi1-xBaxFeO3 samples. Bi1-xBaxFeO3 samples（x = 0.1, 0.2 and 0.3） were synthesized by the conventional solid-state reaction method using nano-powders of Bi2O3, Fe2O3, and BaCO3. Thereafter, field emission scanning electron microscope and X-ray diffraction（XRD） techniques were used to examine the structure and phase of the samples. Phase analysis by XRD indicated that the single-phase perovskite structure was formed with possible increment in lattice parameter with increasing Ba doping. Complex permeability（u＇iand u＇＇i） measured using impedance analyzer confirmed the increase in magnetic property with increasing Ba doping. Finally, dielectric constant（k） was analyzed as a function of temperature at different frequencies. Dielectric constant as high as 2900 was attained in this research for Bi0.8Ba0.2FeO3 sample due to reduction in leakage current at this composition.
文摘Frequency-dependent dielectric constant,dielectric loss,AC conductivity values and complex impedance spectra of V_(2)O_(5)-added Ni-Co-Zn ferrites(Ni_(0.62)Co_(0.03)Zn_(0.35)Fe_(2)O_(4)+xV_(2)O_(5),where x=0,0.5,1 and 1.5 wt.%)have been investigated at room tempera-ture.The dielectric properties of the samples follow the Maxwell-Wagner polarization model.An inverse relationship was found between dielectric constant and AC electrical resistivity for all the samples.The dielectric constants decreased with the addition of V_(2)O_(5),while the electrical resistivities of V_(2)O_(5)-added Ni-Co-Zn ferrites are found to be larger than that of pure Ni-Co-Zn ferrite.The AC conductivity was reduced with the addition of V_(2)O_(5)to Ni-Co-Zn ferrite at lower-frequency region.However,AC conductivity shows a sharp increase at higher-frequency region,which could be attributed to the enhancement of electron hopping between the Fe2+and Fe3+ions in the ferrite matrix due to the activity of the grains.The complex impedance spectroscopy results through Cole-Cole/Nyquist plot have demonstrated a single semicircular arc.It indicates that conduction mechanism takes place predominantly through the grain/bulk property,which could be ascribed to the larger grain size of V_(2)O_(5)-added Ni-Co-Zn ferrites.
