Nd掺杂对磁控溅射Bi_(4-x)Nd_xTi_3O_(12)铁电薄膜结构和性能的影响

Effects of Nd Doping on Structure and Properties of Bi_(4-x)Nd_xTi_3O_(12) Ferroelectric Thin Films

采用磁控溅射工艺在p-Si衬底上制备了Bi4-xNdxTi3O12铁电薄膜,研究了Nd掺杂对Bi4-xNdxTi3O12薄膜微观结构、介电和铁电性能的影响。结果表明,Nd掺杂并未改变薄膜的晶格对称性,仍然保持Bi层状钙钛矿结构,但能在一定程度上抑制晶粒的生长,使薄膜的晶粒更加细小、均匀,同时能明显改善薄膜的介电、铁电性能。Nd掺杂量x=0.30～0.40时,Bi4-xNdxTi3O12薄膜的综合性能较好,其介电常数εr>250,介电损耗tanδ<0.1,剩余极化Pr=20.6μC/cm2,Ec<150 kV/cm。Ag/Bi4-xNdxTi3O12/p-Si异质结顺时针回滞的C-V曲线表明该异质结可实现极化存储,其记忆窗口达1.6 V。但掺杂量不宜过多,当Nd掺杂量达到0.45以后,薄膜的介电、铁电性能反而有所下降。

Bi4-xNdxTi3O12 ferroelectric films fabricated on p-Si substrates by magnetron sputtering.The effects of Nd doping on structure and properties of Bi4-xNdxTi3O12 films were investigated.Bi4-xNdxTi3O12 films had the same structure as Bi4Ti3O12 with smaller and more uniform grains.The dielectric and ferroelectric properties of Bi4-xNdxTi3O12 films were improved by Nd doping.Bi4-xNdxTi3O12 films have better dielectric and ferroelectric properties with Pr = 20.6 μC/cm2,Ec < 150 kV/cm,εr > 250,tanδ < 0.1 and clockwise C-V curves of Ag/Bi4-xNdxTi3O12/ p-Si with a memory window of 1.6 V when x = 0.300.40,while an excessive Nd(x > 0.45) doping would lead to bad dielectric and ferroelectric properties.