Long-range antiferromagnetic order in epitaxial Mn2GaC thin films from neutron reflectometry
Long-range antiferromagnetic order in epitaxial Mn2GaC thin films from neutron reflectometry
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DOI：
10.1103/physrevb.94.024416
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发表时间：
2016-07-13
影响因子：
3.7
通讯作者：
Rosen, J.
中科院分区：
文献类型：
--
作者：
Ingason, A. S.;Palsson, G. K.;Rosen, J.
所谓的最大磁相中的磁结构的性质是一个有争议的话题。在这里，我们给出了3.4K到290.0 K的未极化的中子衍射数据和Q=0.01.1埃(-1)之间的动量转移数据，以及最大相材料Mn2GaC的外延薄膜的补充X射线衍射数据。这种本征层状材料的中子衍射峰与长程反铁磁序一致，周期为两个结构单胞。在整个测量的温度范围内都存在磁结构。计算结果与第一性原理对该材料反铁磁结构的计算结果相一致，在这种结构中，发现Mn-C-Mn原子三层在内部是铁磁耦合的，但在Ga层中发生自旋翻转或旋转。这一发现对关于磁极大相磁结构的性质的讨论具有重要意义。
The nature of the magnetic structure in magnetic so-called MAX phases is a topic of some controversy. Here we present unpolarized neutron-diffraction data between 3.4 and 290.0 K and momentum transfer between Q = 0.0 and 1.1 angstrom(-1), as well as complementary x-ray-diffraction data on epitaxial thin films of the MAX phase material Mn2GaC. This inherently layered material exhibits neutron-diffraction peaks consistent with long-ranged antiferromagnetic order with a periodicity of two structural unit cells. The magnetic structure is present throughout the measured temperature range. The results are in agreement with first-principles calculations of antiferromagnetic structures for this material where the Mn-C-Mn atomic trilayers are found to be ferromagnetically coupled internally but spin flipped or rotated across the Ga layers. The present findings have significant bearing on the discussion regarding the nature of the magnetic structure in magnetic MAX phases.