Preparation and Spontaneous Polarization–Magnetization of a New Ceramic Ferroelectric–Ferromagnetic Composite

Abstract

Ceramic composites with the composition of xPMZNT·(1 –x)NiCuZn have been prepared using a standard ceramic technique, in which x varies as 0, 0.1, 0.2, 0.4, 0.6, 0.9, and 1.0. PMZNT is the abbreviated form of 0.92Pb(Mg1/3Nb2/3)O3·0.04Pb(Zn1/3Nb2/3)O3·0.04PbTiO3 (PMN‐PZN‐PT). NiCuZn is the abbreviated form of Ni0.2Cu0.2Zn0.6Fe2O4. The presence of ferroelectric PMZNT phase and ferromagnetic NiCuZn ferrite phase has been confirmed using X‐ray diffractometry. Ferroelectric hysteresis loops and magnetic hysteresis loops have been observed and studied. In polarization–electric‐field curves, the remnant polarization and coercive fields display little asymmetric characterization because of the existence of the internal electric field. When the amount of NiCuZn ferrite phase increases, the coercive field increases. Meanwhile, the saturation magnetization decreases and the coercivity of the composites increases with the increase of phase fraction of PMZNT, because the interaction between magnetic grains (or magnetic connectivity) is weakened by the existence of nonmagnetic PMZNT phase distributed in the magnetic phases. Under an applied magnetic and electric field, the magnetization and polarization of the composites can be easily tuned. The sintered composites possess high density and fine‐grained microstructure. The average grain size of NiCuZn ferrite grains is slightly larger than that of the PMZNT grains.