The polycrystalline sample of Ba_(2)Mg_(2)Fe_(12)O_(22) was prepared by solid-state reaction technique.Room-temperature X-ray diffraction(XRD)has confirmed the formation of rhombohedral structure.The electrical proper...The polycrystalline sample of Ba_(2)Mg_(2)Fe_(12)O_(22) was prepared by solid-state reaction technique.Room-temperature X-ray diffraction(XRD)has confirmed the formation of rhombohedral structure.The electrical properties of the sample were studied in wide ranges of temperatures and frequencies.The impedance analysis indicates the presence of bulk effect.The bulk resistance of the material decreases with rise in temperature and exhibits NTCR behavior.This compound also exhibits the temperature-dependent non-Debye type of relaxation phenomena.The presence of non-Debye type of relaxation has been confirmed by the complex impedance analysis.The variation of DC conductivity(bulk)with temperature demonstrates that the compound exhibits Arrhenius type of electrical conductivity.The activation energy of the compound is found to be 0.55 eV in high-temperature region.展开更多
Bi_(9-x)Fe_(5+x)Ti_(3)O_(2)7(x=0-3)compounds of bismuth layered perovskite structure have been successfully prepared by solid-state reaction method.X-ray diffraction(XRD)studies revealed the orthorhombic crystal struc...Bi_(9-x)Fe_(5+x)Ti_(3)O_(2)7(x=0-3)compounds of bismuth layered perovskite structure have been successfully prepared by solid-state reaction method.X-ray diffraction(XRD)studies revealed the orthorhombic crystal structure of all the compounds.Impedance spectroscopy has been stu-died to characterize the electrical properties of polycrystalline Bi_(9-x)Fe_(5+x)Ti_(3)O_(2)7(x=0-3)compounds.The shape of complex impedance curves inferred the contribution of bulk and grain boundary effects on the electrical properties of the compounds.Temperature dependent magne-tization measurements were made from 2 K to 300 K.Narrow hysteresis loops observed at room temperature indicate antiferromagnetic behavior of the compounds.展开更多
文摘The polycrystalline sample of Ba_(2)Mg_(2)Fe_(12)O_(22) was prepared by solid-state reaction technique.Room-temperature X-ray diffraction(XRD)has confirmed the formation of rhombohedral structure.The electrical properties of the sample were studied in wide ranges of temperatures and frequencies.The impedance analysis indicates the presence of bulk effect.The bulk resistance of the material decreases with rise in temperature and exhibits NTCR behavior.This compound also exhibits the temperature-dependent non-Debye type of relaxation phenomena.The presence of non-Debye type of relaxation has been confirmed by the complex impedance analysis.The variation of DC conductivity(bulk)with temperature demonstrates that the compound exhibits Arrhenius type of electrical conductivity.The activation energy of the compound is found to be 0.55 eV in high-temperature region.
文摘Bi_(9-x)Fe_(5+x)Ti_(3)O_(2)7(x=0-3)compounds of bismuth layered perovskite structure have been successfully prepared by solid-state reaction method.X-ray diffraction(XRD)studies revealed the orthorhombic crystal structure of all the compounds.Impedance spectroscopy has been stu-died to characterize the electrical properties of polycrystalline Bi_(9-x)Fe_(5+x)Ti_(3)O_(2)7(x=0-3)compounds.The shape of complex impedance curves inferred the contribution of bulk and grain boundary effects on the electrical properties of the compounds.Temperature dependent magne-tization measurements were made from 2 K to 300 K.Narrow hysteresis loops observed at room temperature indicate antiferromagnetic behavior of the compounds.
