Detection of stacking faults breaking the [110]/[110] symmetry in ferromagnetic semiconductors (Ga,Mn)As and (Ga,Mn)(As,P)
Detection of stacking faults breaking the [110]/[110] symmetry in ferromagnetic semiconductors (Ga,Mn)As and (Ga,Mn)(As,P)
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DOI：
10.1103/physrevb.83.235324
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发表时间：
2010-12
影响因子：
3.7
通讯作者：
M. Kopecký;J. Kub;F. Máca;J. Masek;O. Pacherova;A. Rushforth;B. Gallagher;R. Campion;V. Novák
中科院分区：
文献类型：
--
作者：
M. Kopecký;J. Kub;F. Máca;J. Masek;O. Pacherova;A. Rushforth;B. Gallagher;R. Campion;V. Novák
我们报道了（Ga,Mn）As和（Ga,Mn）（As，P）薄膜的高分辨率x射线衍射测量。我们观察到（111）和（111）面存在层错的结构各向异性，而（111）和（111）面不存在层错。它们占铁磁脱膜体积的10{sup -2}%-10{sup -1}%，而在控制的、未掺杂的GaAs脱膜中没有检测到层错。全势密度泛函计算提供了额外的证据，表明这些结构缺陷吸引的Mn促进了层错的形成。沿着层错面的公共[110]方向增强的Mn密度产生了一种强度和意义上的对称性破坏机制，可以解释这些铁磁半导体的单轴[110]/[110]磁晶各向异性。
We report on high-resolution x-ray diffraction measurements of (Ga,Mn)As and (Ga,Mn)(As,P) epilayers. We observe a structural anisotropy in the form of stacking faults that are present in the (111) and (111) planes and absent in the (111) and (111) planes. They occupy 10{sup -2}%-10{sup -1}% of the ferromagnetic epilayer volume while no stacking faults are detected in the controlled, undoped GaAs epilayer. Full-potential density functional calculations provide additional evidence that the formation of the stacking faults is promoted by Mn attracted to these structural defects. The enhanced Mn density along the common [110] direction of the stacking fault planes produces a symmetry-breaking mechanism of a strength and sense that can account for the uniaxial [110]/[110] magnetocrystalline anisotropy of these ferromagnetic semiconductors.