Tristate ferroelectric memory and strain memory in Bi_(1/2)Na_(1/2)TiO_3-based relaxor ferroelectrics

摘要

Tristate ferroelectric memory and strain memory of Bi1/2Na1/2TiO3 (BNT)-based relaxor ferroelectrics are proposed. These memory effects can be realized in BNT-based materials with double-like P-E hysteresis loops and obvious non-zero remanent polarization. An underlying triple-well free-energy landscape, in which the relaxor state serves as an intermediate stable state between two ferroelectric remanent states, is thought to be responsible for such a ferroelectric behavior and provides the basis for the tristate ferroelectric memory effect. Besides, the strain memory effect utilizes the inherent strain difference between relaxor and ferroelectric states. Experimental verifications on Bi-1/2(Na0.8K0.2)(1/2)(Ti0.955Fe0.030Nb0.015)O-3 ceramics show that the tristate ferroelectric memory and the strain memory can be operated as proposed, and the programmability and the retention ability of both effects are fairly good. The present study provides a facile approach to the multistate ferroelectric memory and shape memory piezoelectric actuator applications. Published by AIP Publishing.