Preparation of Composite Ceramics of NiFe_2O_4/PZT by Sol-Gel Method and Their Magnetoelectric Effect

摘要

The precursor powder of lead-zirconate-titanate (PZT) and NiFe_2O_4 (NFO) was prepared using one step sol-gel method. The dry powders got after a series of processes were sintered via a conventional ceramic solid-state reaction technique. All the diffraction peaks in the XRD patterns of the composites can be readily indexed to NFO and PZT, respectively. The SEM micrograph shows two different phases of PZT and NFO distinctly and the particle size of NFO was about 2～4 μm. The magnetoelectric (ME) coefficient, dielectric constant, piezoelectric constant, magnetic hysteresis loops of the samples were measured. The dc magnetic H_(dc) resulting in the maximum ME coefficient varies from 0.65kOe to 1.0kOe with the increase of the NFO volume fraction. The maximum magnetoelectric coefficient of 6.15Vcm~(-1)Oe~(-1) was obtained at resonance frequency of 289.8kHz, dc magnetic intensity of 0.8kOe and NFO volume fraction of 0.25.