Anisotropic lattice changes and ferromagnetic order in Sr 1 − x Ca x RuO 3
Anisotropic lattice changes and ferromagnetic order in Sr 1 − x Ca x RuO 3
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DOI：
10.1103/physrevb.83.144430
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发表时间：
2011-04
影响因子：
3.7
通讯作者：
M. Wissinger;D. Fuchs;L. Dieterle;H. Leiste;R. Schneider;D. Gerthsen;H. Löhneysen
中科院分区：
文献类型：
--
作者：
M. Wissinger;D. Fuchs;L. Dieterle;H. Leiste;R. Schneider;D. Gerthsen;H. Löhneysen
在（001）取向和（）取向单晶衬底上的外延薄膜分别经历了< 0.5和0.9的共格压应变，形成了近四晶结构。相对于相应块体材料的伪立方结构，薄膜（0）的四元畸变/增加高达2.4%。增加压缩应变导致，独立的Ca取代的程度，到一个连续的收缩的晶胞体积。对于常数，在压缩（拉伸）应变下的膜显示铁磁居里温度的降低（增加）相比，体值。的变化被发现是强烈相关的单位细胞体积的减少，即，K/，几乎是独立的。值得注意的是，双轴外延压力导致几乎相同的值，推导出的bulkunder各向同性静水压力。鉴于存在于四边形扭曲薄膜中的强磁各向异性，其中压缩应变显著增强了面外磁化，这是相当令人惊讶的结果。对于适度的外延应变的tetraphite变形似乎只发挥一个较小的作用reducedin薄膜。
Thin epitaxial films ofon (001)-orientedand ()()single-crystal substrates experience coherent compressive strain for< 0.5 and 0.9, respectively, resulting in a nearly tetragonal structure. The tetragonal distortion/increases forfilms (0) up to 2.4% with respect to the pseudocubic structure of the corresponding bulk material. Increasing compressive strain leads, independently of the degree of Ca substitution, to a successive shrinkage of the unit-cell volume. For constant, films under compressive (tensile) strain show a decrease (increase) of the ferromagnetic Curie temperaturecompared to the bulk value. The change ofis found to be strongly correlated to the decrease of the unit-cell volume, i.e.,K/, nearly independent of. Remarkably, the biaxial epitaxial pressure leads to nearly the same value ofas deduced for bulkunder isotropic hydrostatic pressure. In view of the strong magnetic anisotropy present in the tetragonally distorted thin films, where compressive strain enhances the out-of-plane magnetization significantly, this is a rather surprising result. For moderate epitaxial strain the tetragonal distortion seems to play only a minor role for the reducedin thin films.