Large magnetocrystalline anisotropy in tetragonally distorted Heuslers: a systematic study
Large magnetocrystalline anisotropy in tetragonally distorted Heuslers: a systematic study
复制标题
DOI：
10.1088/1361-6463/aa5441
复制
发表时间：
2017-02
期刊：
影响因子：
--
通讯作者：
Y. Matsushita;Y. Matsushita;G. Madjarova;G. Madjarova;J. K. Dewhurst;S. Shallcross;C. Felser;Sangeeta Sharma;Sangeeta Sharma;E. Gross
中科院分区：
文献类型：
--
作者：
Y. Matsushita;Y. Matsushita;G. Madjarova;G. Madjarova;J. K. Dewhurst;S. Shallcross;C. Felser;Sangeeta Sharma;Sangeeta Sharma;E. Gross
鉴于没有稀土的硬磁体的设计，我们探索的可能性，大磁晶各向异性能量的Heusler化合物是不稳定的相对于一个tetraorbital失真。我们考虑Heusler化合物Fe 2 YZ与Y =（Ni，Co，Pt），和Co2 YZ与Y =（Ni，Fe，Pt），其中，在这两种情况下，Z =（Al，Ga，Ge，In，Sn）.我们发现，对于Co_2NiZ，Co_2PtZ和Fe_2PtZ族的立方相总是，在T = 0时，相对于四角畸变是不稳定的，而相反，对于Fe_2NiZ和Fe_2CoZ族，这是只有两种化合物-Fe_2NiGe和Fe_2NiSn的情况。我们计算了所有发生四重畸变的化合物的磁晶各向异性能（MAE），发现含铂的赫斯勒化合物的MAE值非常大，但其他一些化合物的MAE值也很大（例如Co2 NiGa的MAE为-2.38 MJ m-3）。我们发现，在立方相的费米能级的高密度的状态（DOS）的倾向，一个tetravel失真是强烈相关的。作为这一事实的必然结果，我们观察到，在掺杂化合物的立方结构是稳定的，使费米能级进入高DOS的区域，诱导的tetraorthane失真，然后观察到相应的大值的MAE。
With a view to the design of hard magnets without rare earths we explore the possibility of large magnetocrystalline anisotropy energies in Heusler compounds that are unstable with respect to a tetragonal distortion. We consider the Heusler compounds Fe2YZ with Y = (Ni, Co, Pt), and Co2YZ with Y = (Ni, Fe, Pt) where, in both cases, Z = (Al, Ga, Ge, In, Sn). We find that for the Co2NiZ, Co2PtZ, and Fe2PtZ families the cubic phase is always, at T = 0, unstable with respect to a tetragonal distortion, while, in contrast, for the Fe2NiZ and Fe2CoZ families this is the case for only 2 compounds—Fe2NiGe and Fe2NiSn. For all compounds in which a tetragonal distortion occurs we calculate the magnetocrystalline anisotropy energy (MAE) finding remarkably large values for the Pt containing Heuslers, but also large values for a number of the other compounds (e.g. Co2NiGa has an MAE of −2.38 MJ m−3). The tendency to a tetragonal distortion we find to be strongly correlated with a high density of states (DOS) at the Fermi level in the cubic phase. As a corollary to this fact we observe that upon doping compounds for which the cubic structure is stable such that the Fermi level enters a region of high DOS, a tetragonal distortion is induced and a correspondingly large value of the MAE is then observed.