Tetragonal-tetragonal-monoclinic-rhombohedral transition: Strain relaxation of heavily compressed BiFeO3 epitaxial thin films
Tetragonal-tetragonal-monoclinic-rhombohedral transition: Strain relaxation of heavily compressed BiFeO3 epitaxial thin films
复制标题
四方-四方-单斜-菱面体转变：重度压缩的 BiFeO3 外延薄膜的应变弛豫
DOI：
10.1063/1.4864077
复制
发表时间：
2014-02-03
影响因子：
4
通讯作者：
Wu, J. L.
中科院分区：
文献类型：
--
作者：
Fu, Z.;Yin, Z. G.;Wu, J. L.
在缺氧的La0.3Sr0.7MnO3-delta缓冲的SrTiO 3（001）衬底上沉积了面内压应变为-3.5%的BiFeO 3薄膜。这种高度应变的BiFeO 3不直接松弛到其菱形母体相时，增加膜厚度。相反，观察到一个多步骤的路径，涉及结构转变。错配应力首先通过c/a比为1.23的真四方晶系BiFeO 3的出现来调节，然后通过向M-C型单斜结构的转变来降低，最后通过M-C-菱面体转变来缓解。此外，该过程使得能够在远低于报道的约4.5%的阈值的应力水平下形成应变驱动的准同型相边界。(C)2014 AIP出版有限责任公司。
BiFeO3 films with in-plane compressive strain of -3.5% were deposited on oxygen-deficient La0.3Sr0.7MnO3-delta buffered SrTiO3(001) substrates. This highly strained BiFeO3 does not relax directly into its rhombohedral parent phase upon increasing the film thickness. Instead, a multi-step path involving structural transitions is observed. The misfit stress is first accommodated by the occurrence of true tetragonal BiFeO3 with c/a ratio of 1.23, then reduced by the transformation to the M-C-type monoclinic structure, and finally alleviated through the M-C-rhombohedral transition. Moreover, this process enables the formation of strain-driven morphotropic phase boundaries at a stress level much lower than the reported threshold of -4.5%. (C) 2014 AIP Publishing LLC.