Layered perovskites with giant spontaneous polarizations for nonvolatile memories.
A series of titanate-based layered perovskites having large values of the spontaneous polarization P(s) were developed for their applcations to nonvolatile ferroelectric random access memories. Among these, the Nd-modified bismuth titanate [Bi(4-x)Nd(x)Ti(3)O(12) (BNdT)] system exhibited the most remarkable ferroelectric properties. The c-axis oriented BNdT capacitor was characterized by a switchable remanent polarization 2P(r) of over 100 microC/cm(2) and imprinting and fatigue-free behavior. The active Ti site responsible for the giant P(s) was identified with the help of Rietveld analysis, x-ray absorption near-edge structure study, and ab initio quantum computations.
Department of Materials Science and Engineering, and National Research Laboratory for Ferroelectric Phase Transitions, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
Uong
U
Chon
Hyun M
HM
Jang
M G
MG
Kim
C H
CH
Chang