Coexistence of ergodicity and nonergodicity in LaFeO3-modified Bi(1/2)(Na(0.78)K(0.22))(1/2)TiO3 relaxors.
The effect of LaFeO(3) addition to Bi(1/2)(Na(0.78)K(0.22))(1/2)TiO(3) ceramics on the phase stability and macroscopic functional properties was investigated. Similarly to other chemical modifiers known in the literature, LaFeO(3) addition suppresses an electric-field-induced long-range ferroelectric order, giving rise to a giant unipolar strain of ~0.3% at 2 mol% LaFeO(3) addition. Time-dependent changes in polarization and strain hysteresis loops both during successive electrical cycling and after removal of the electric field suggest that a specimen with 2 mol% LaFeO(3) consists of both ergodic and nonergodic phases, which is unique among the known relaxor materials.
School of Materials Science and Engineering, University of Ulsan, Ulsan 680-749, Republic of Korea.
Hyoung-Su
HS
Han
Wook
W
Jo
Jürgen
J
Rödel
In-Ki
IK
Hong
Weon-Pil
WP
Tai
Jae-Shin
JS
Lee