稀土掺杂Bi4Ti3O12铁电薄膜取向生长回线动力学研究

Study on Kinetics of Orientation Growth of Rare Earth Doped Bi4Ti3O12 Ferroelectric Thin Films

稀土掺杂层状钙钛矿结构的Bi4Ti3O12铁电薄膜具有居里温度高,自发极化大,耐疲劳性好的特点,适用于制作铁电储存器。由于Bi4Ti3O12铁电薄膜的自发极化矢量靠近a轴,近a轴生长的Bi4Ti3O12铁电薄膜具有大的剩余极化强度。对比研究了随机取向Bi4Ti3O12铁电薄膜和a/b轴择优取向Bi4Ti3O12铁电薄膜的回线动力学标度。结果表明a/b轴高择优取向度的Bi4Ti3O12铁电薄膜的标度关系为:低频段∝f 0.043E00.8;高频段∝f-0.21E00.8。a/b轴低择优取向度的Bi4Ti3O12铁电薄膜的标度关系为:∝f-0.05E00.917。随机取向Bi4Ti3O12铁电薄膜的标度关系在高频和低频统一为∝f-0.07E01.31。

The rare-earth doped ferroelectric Bi4Ti3O12 of layered-perovskite which has high Curie temperature, large spontaneous polarization and good fatigue resistance, is one of the candidate materials for nonvolatile ferroelectric memory application. Due to the spontaneous polarization of the Bi4Ti3O12 thin films is close to the a-axis, the a-axis (or near a-axis) growth Bi4Ti3O12 thin films has a large remanent polarization. The scaling behavior of the dynamic hysteresis on a/b-axes oriented and randomly oriented Bi4Ti3O12 thin films was investigated. The scaling relations of a/b-axes oriented Bi4Ti3O12 of high preferential orientation degree thin films were ∝ f 0.043E00.8 when f < 1/te and ∝f -0.21E00.8 when f > 1/te.The scaling relations of a/b-axes oriented Bi4Ti3O12 of low preferential ori. entation degree thin films were ∝f - 0.05E00.917. The scaling relations of randomly oriented Bi4Ti3O12 thin films were ∝f - 0.07E01.31.