Particulate composites of ferrite and ferroelectric phases with xNiFe(2)O(4) (NF) and (1-x)Pb-0.988 (Zr0.52Ti0.48)(0.976)Nb0.024O3 (where x = 2, 10, 20, 30, 50, 70, and 100 wt. %) were prepared in situ by sol-gel method. The presence of a diphase composition was confirmed by X-ray diffraction while the microstructure of the composites was studied by scanning electron microscopy revealing a good mixing of the two phases and a good densification of the bulk ceramics. The dielectric permittivity shows usual dielectric dispersion behavior with increasing frequency due to Maxwell-Wagner interfacial polarization. AC conductivity measurements made in frequency range 1 Hz-1 MHz suggest that the conduction process is due to mixed polaron hopping. The effect of NF phase concentration on the P-E and M-H hysteresis behavior and dielectric properties of the composites was investigated. At low NF concentration a sharp ferro-paraelectric transition peak can be observed at around 360 degrees C while for higher NF concentrations a trend to a diffuse phase transition occurs. All the composite samples exhibit typical ferromagnetic hysteresis loops, indicating the presence of ordered magnetic structure. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4792494]
Ferroelectric and dielectric properties of ferrite-ferroelectric ceramic composites
Galassi;Carmen;
2013
Abstract
Particulate composites of ferrite and ferroelectric phases with xNiFe(2)O(4) (NF) and (1-x)Pb-0.988 (Zr0.52Ti0.48)(0.976)Nb0.024O3 (where x = 2, 10, 20, 30, 50, 70, and 100 wt. %) were prepared in situ by sol-gel method. The presence of a diphase composition was confirmed by X-ray diffraction while the microstructure of the composites was studied by scanning electron microscopy revealing a good mixing of the two phases and a good densification of the bulk ceramics. The dielectric permittivity shows usual dielectric dispersion behavior with increasing frequency due to Maxwell-Wagner interfacial polarization. AC conductivity measurements made in frequency range 1 Hz-1 MHz suggest that the conduction process is due to mixed polaron hopping. The effect of NF phase concentration on the P-E and M-H hysteresis behavior and dielectric properties of the composites was investigated. At low NF concentration a sharp ferro-paraelectric transition peak can be observed at around 360 degrees C while for higher NF concentrations a trend to a diffuse phase transition occurs. All the composite samples exhibit typical ferromagnetic hysteresis loops, indicating the presence of ordered magnetic structure. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4792494]I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
