BaTiO_3-(Ni_(0.5)Zn_(0.5))Fe_2O_4 ceramic composites with ferroelectric and magnetic properties

摘要

Di-phase ceramic composites 0.50BaTiO_3-0.50Ni_(0.5)Zn_(0.5)Fe_2O_4 with limited reaction at interfaces prepared by two methods: (i) mixing BaTiO_3 and Ni_(0.5)Zn_(0.5)Fe_2O_4 powders and (ii) co-precipitation of Fe, Ni, Zn salts in solutions containing BaTiO_3 powders, are comparatively analysed. Homogeneous microstructures with higher density and better mixing of the two phases are obtained by the second method and consequently, better dielectric properties (tan delta < 5 percent and epsilon_r implied by 300-800 for/> 10~4 Hz at room temperature) and higher magnetic moments. Some interface effects are playing important roles on the dielectric properties at low frequencies and high temperatures, mainly in the samples prepared following the method (i). Both the ferroelectric and magnetic phases preserve their basic properties in the bulk composite form and thus, these composites BT-NZF are good candidates as magnetoelectric materials.