Relation between the Crystal Structure, Physical Properties and Ferroelectric Properties of PbZrxTi1-xO3(x=0.40, 0.45, 0.53) Ferroelectric Material by Heat Treatment

Abstract

Ferroelectric random access memory (FeRAM) is expected to be the next generation memory. PbZrxTi1−xO3 (PZT) is considered as a candidate because of its high remanent polarization (Pr). We investigated the relation between physical properties, crystal structure and ferroelectric performance of the sample before and after various heat treatments. From the results, remanent polarization (Pr) and coercive field (Ec) increased with increasing PO2 during heat treatment. The remanent polarization (Pr) and coercive field (Ec) decreased with increasing Zr content x. Furthermore, the dielectric constants at room temperature increased with increasing Zr content x. On the other hand, Curie Temperature (TC) increased with decreasing Zr content x or increasing PO2 during heat treatment. From the structural analysis, the bond length of M(Zr,Ti)-O1 decreased with increasing PO2 during heat treatment or with decreasing Zr content x of pre-heated samples. Consequently, the ferroelectric performance was affected by changing the defect of oxygen and the strain of the structure.