Structure of epitaxial Ca2Fe2O5 films deposited on different perovskite-type substrates
Structure of epitaxial Ca2Fe2O5 films deposited on different perovskite-type substrates
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DOI：
10.1063/1.1689003
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发表时间：
2004-04
影响因子：
3.2
通讯作者：
M. Rossell;O. Lebedev;G. Tendeloo;N. Hayashi;T. Terashima;M. Takano
中科院分区：
文献类型：
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作者：
M. Rossell;O. Lebedev;G. Tendeloo;N. Hayashi;T. Terashima;M. Takano
用透射电子显微镜研究了衬底对Ca2Fe2O5（CFO）薄膜结构和显微结构的影响。采用脉冲激光沉积法在（001）取向的SrTiO_3（STO）、LaAl_3（LAO）和（LaAl_3）_（0.3）（SrAl_（0.5）Ta_（0.5）O_3）_（0.7）（LSAT）衬底上制备了Ca_2Fe_2O_5薄膜。CFO膜与三种不同衬底的晶格失配的微小变化强烈地决定了膜的生长方向。错配应力也促进了应变适应机制的发展。(101)在STO（001）和LSAT（001）上形成“正交”孪晶以适应CFO外延膜中的失配，而在LAO（001）上的CFO膜发展90°旋转孪晶，导致膜破碎成晶粒。在LAO上的CFO薄膜的生长方向不仅取决于晶格失配，而且还取决于在生长过程的初始阶段所涉及的晶格能。我们的研究结果还证明了一个意想不到的相的形成与组成Ca3Fe2.
The influence of the substrate on the structure and the microstructure of Ca2Fe2O5 (CFO) thin films has been investigated by transmission electron microscopy. Ca2Fe2O5 films have been deposited by pulsed laser deposition on (001)-oriented SrTiO3 (STO), LaAlO3 (LAO), and (LaAlO3)0.3(SrAl0.5Ta0.5O3)0.7 (LSAT) substrates. Minor variations in the lattice mismatch of the CFO film with the three different substrates strongly determine the growth direction of the film. The misfit stress also promotes the development of strain accommodation mechanisms. (101) “orthogonal” twins are formed to accommodate the misfit in epitaxial films of CFO on STO(001) and LSAT(001), while CFO films on LAO(001) develop 90° rotation twins leading to film fragmentation into grains. The growth direction of the CFO film on LAO not only depends on the lattice mismatch but also on the lattice energy involved at the initial stages of the growth process. Our results also evidence the formation of an unexpected phase with composition Ca3Fe2...