Perez Felio A, Borisov Pavel, Johnson Trent A, Stanescu Tudor D, Trappen Robbyn, Holcomb Mikel B, Lederman David, Fitzsimmons M R, Aczel Adam A, Hong Tao
Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315, USA.
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2015 Mar 6;114(9):097201. doi: 10.1103/PhysRevLett.114.097201. Epub 2015 Mar 4.
Three-dimensional antiferromagnets with random magnetic anisotropy (RMA) that have been experimentally studied to date have competing two-dimensional and three-dimensional exchange interactions which can obscure the authentic effects of RMA. The magnetic phase diagram of Fe_{x}Ni_{1-x}F_{2} epitaxial thin films with true random single-ion anisotropy was deduced from magnetometry and neutron scattering measurements and analyzed using mean-field theory. Regions with uniaxial, oblique, and easy-plane anisotropies were identified. A RMA-induced glass region was discovered where a Griffiths-like breakdown of long-range spin order occurs.
迄今为止，已对具有随机磁各向异性（RMA）的三维反铁磁体进行了实验研究，其二维和三维交换相互作用相互竞争，这可能会掩盖RMA的真实效应。通过磁力测量和中子散射测量推导了具有真正随机单离子各向异性的FeₓNi₁₋ₓF₂外延薄膜的磁相图，并使用平均场理论进行了分析。确定了具有单轴、倾斜和易平面各向异性的区域。发现了一个RMA诱导的玻璃区域，其中发生了类似格里菲斯的长程自旋序破坏。
