Double epitaxy of tetragonal and hexagonal phases in the FeSe system
Double epitaxy of tetragonal and hexagonal phases in the FeSe system
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DOI：
10.1016/j.jcrysgro.2019.01.031
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发表时间：
2019-05-15
影响因子：
1.8
通讯作者：
Camata, R. P.
中科院分区：
文献类型：
--
作者：
Harris, S. B.;Camata, R. P.
外延薄膜含有一个以上的结晶相或取向的兴趣，由于改变的磁，电，和光学性能的可能性。薄膜的FeSe已生长在单晶MgO衬底上的条件下，产生的同时，外延生长的四角和六角相。我们发现，这种双外延的特点是具有良好定义的外延相互关系的相域，并且可以控制相对相分数。对于350-450 ℃的生长温度，（0 0 1）取向的四方相（β-FeSe）以其晶胞与立方衬底对齐的方式生长，而（1 0 1）取向的六方相（Fe 7Se 8）显示具有两个不同的面内取向的畴，所述两个不同的面内取向相隔45度。此外，β-FeSe相可以选择为相对于衬底为（0 0 1）-或（1 0 1）-取向，其中（1 0 1）取向包含三个旋转畴。
Epitaxial films which contain more than one crystallographic phase or orientation are of interest due to the possibility of altered magnetic, electrical, and optical properties. Thin films of FeSe have been grown on single-crystal MgO substrates under conditions that produce the simultaneous, epitaxial growth of tetragonal and hexagonal phases. We show that this double epitaxy is characterized by phase domains with a well-defined epitaxial relationship to each other and that the relative phase fraction can be controlled. For growth temperatures of 350-450 degrees C, the (0 0 1)-oriented tetragonal phase (beta-FeSe) grows with its unit cell aligned with the cubic substrate, while a (1 0 1)-oriented hexagonal phase (Fe7Se8) shows domains with two different in-plane orientations separated by 45 degrees. Additionally, the beta-FeSe phase can be chosen to be (0 0 1)- or (1 0 1)-oriented with respect to the substrate, with the (1 0 1) orientation containing three rotated domains.