Jekal Soyoung, Kwon Oryong, Hong Soon Cheol, Lee Jae Il
J Nanosci Nanotechnol. 2015 Mar;15(3):2356-9. doi: 10.1166/jnn.2015.10264.
A bulk d0 NaN of rocksalt or zinc-blende structure was predicted to be a ferromagnetic half metal and furthermore the half-metallicity would be retained in thin films. Such half metallicity of d0 ferromagnetic NaN is attractive for possible application in a spintronics device, such as a spin transfer torque magnetic random access memory. In this study, we carried out first-principles calculations on magnetocrystalline anisotropy rocksalt structured NaN thin films with different thicknesses, using Vienna Ab-initio Simulation Package code. It was found that the NaN(001) thin films have perpendicular magnetization with quite low magnetocrystalline anisotropy energies of order of 10 µeV, but capping of a 5d-transition metal Ta monolayer over the NaN(001) thin films enhances the perpendicular magnetocrystalline anisotropy energies significantly, more than 10 times. Furthermore, the 1 (Ta)/NaN(001) systems retain their half-metallicity except the NaN layer just below Ta.
预测具有岩盐或闪锌矿结构的大量d0NaN是一种铁磁半金属，而且这种半金属性在薄膜中也会保留。d0铁磁NaN的这种半金属性对于自旋电子器件（如自旋转移矩磁随机存取存储器）的可能应用具有吸引力。在本研究中，我们使用维也纳从头算模拟包代码对不同厚度的具有岩盐结构的NaN磁性薄膜进行了第一性原理计算。结果发现，NaN(001)薄膜具有垂直磁化，其磁晶各向异性能量相当低，约为10μeV量级，但在NaN(001)薄膜上覆盖一层5d过渡金属Ta单层会显著提高垂直磁晶各向异性能量，提高了10倍以上。此外，1(Ta)/NaN(001)体系除了Ta下方紧邻的NaN层外，其余部分都保持其半金属性。
