Author/Authors :
Song، نويسنده , , C.H. and Li، نويسنده , , W. and Ma، نويسنده , , J. and Gu، نويسنده , , J. and Yao، نويسنده , , Y.Y. and Feng، نويسنده , , Y. and Lu، نويسنده , , X.M. and Zhu، نويسنده , , J.S. and Wang، نويسنده , , Y.N. and Chan، نويسنده , , W.L.H. and Choy، نويسنده , , C.L.، نويسنده ,
Abstract :
Bi4Ti3O12 (BiT), Bi3.25La0.75Ti3O12 (BLT), Bi4−x/3Ti3−xNbxO12 (BTN) and Bi3.25−x/3La0.75Ti3−xNbxO12 (BLTN) thin films have been prepared by pulsed laser deposition. BTN and BLTN films exhibit a maximum in the remanent polarization Pr at a Nb content x=0.018. At this Nb content, the BLTN film has a Pr value (25 μC/cm2) that is much higher than that of BiT and a coercive field (Ec=120 kV/cm) similar to that of BiT. The polarization of this BLTN film is fatigue-free up to 109 switching cycles. The high fatigue resistance is mainly due to the substitution of Bi3+ ions by La3+ ions at the A site and the enhanced Pr arises largely from the replacement of Ti4+ ions by Nb5+ ions at the B site. The mechanisms behind the effects of the substitution at the two sites are discussed.
