Effect of hafnium on the microstructure, dielectric and ferroelectric properties of Ba[Zr_(0.2)Ti_(0.8)]O_3 ceramics

摘要

Hafnium (Hf)-doped Ba[Zr_(0.2)Ti_(0.8)]O_3 (BZT) ceramics were prepared by the conventional solid-state reaction method. The microstructure, dielectric and ferroelectric properties of Hf-doped BZT ceramics have been investigated. Hf~(4+) ions enter the perovskite-type cubic structure to substitute for Ti~(4+) ions on the B sites and lead to the increase of the lattice parameter. Addition of hafnium can restrain grain growth in the BZT ceramics. Hf-doped BZT ceramics have ferroelectric properties with diffuse phase transition. Hf~(4+) ions can reduce dielectric loss of BZT ceramics. As Hf content increases, the remnant polarization begins to increase to the maximum and then decrease, while the coercive field begins to decrease to the minimum and then increase. The remnant polarization, saturation polarization and coercive field decrease with the rise of measurement temperature.