Reentrant surface anisotropy in the antiferromagnetic/ferromagnetic bilayer Mn/Co/Cu(001).
Reentrant surface anisotropy in the antiferromagnetic/ferromagnetic bilayer Mn/Co/Cu(001).
复制标题
DOI：
10.1103/physrevlett.112.037201
复制
发表时间：
2014-01
影响因子：
8.6
通讯作者：
M. Caminale;R. Moroni;P. Torelli;W. C. Lin;M. Canepa;L. Mattera;F. Bisio
中科院分区：
文献类型：
--
作者：
M. Caminale;R. Moroni;P. Torelli;W. C. Lin;M. Canepa;L. Mattera;F. Bisio
研究了生长在邻位Cu（001）表面上的反铁磁/铁磁（AF/FM）Mn/Co双层外延膜中单原子表面台阶原子的磁各向异性能。Co/Cu（001）薄膜的阶跃诱导各向异性在亚单层Mn沉积时被淬灭，但在1 ~ 2单层Mn厚度（tMn）之间观察到凹入的单轴表面各向异性，当Mn厚度超过2单层时，这种各向异性消失。在Mn/Co/Cu（001）体系中，Mn膜在1-2 Mn单层厚度范围内经历了一个依赖于tMn的从FM到AF的转变，这使得膜中FM和AF Mn相共存。一个相当大的单轴各向异性专门在Mn的FM和AF相共存的厚度范围内的观察指出FM和AF区域之间的边界在Mn膜的关键作用。因此，提出了一种磁型的磁破裂机制，而不是一种纯粹的几何机制，作为重入各向异性的起源。
We investigated the magnetic anisotropy energy of monatomic surface-step atoms in antiferromagnetic/ferromagnetic (AF/FM) epitaxial Mn/Co bilayers grown on vicinal Cu(001) surfaces. The step-induced anisotropy of the Co/Cu(001) films was quenched upon submonolayer Mn deposition, but a reentrant uniaxial surface anisotropy was observed for Mn thickness (tMn) between 1 and 2 monolayers, which disappears for Mn thickness above 2 monolayers. In the Mn/Co/Cu(001) system, Mn films undergo a tMn-dependent transition from FM to AF in the 1-2 Mn monolayer thickness range, which entails the coexistence of FM and AF Mn phases in the film. The observation of a sizeable uniaxial anisotropy exclusively in the Mn-thickness range of coexistence of the FM and AF phases points out the crucial role of the boundaries between FM and AF regions within the Mn film. A symmetry-breaking mechanism of a magnetic type, rather than a purely geometric one, is therefore proposed as the origin of the reentrant anisotropy.