论文标题
tb $ _ {1-x} $ dy $ _ {x} $ fe $ _ {2} $从第一原理
Spin orientation and magnetostriction of Tb$_{1-x}$Dy$_{x}$Fe$_{2}$ from first principles
论文作者
论文摘要
高度磁性的稀有稀土化合物TB $ _ {1-X} $ dy $ _x $ _x $ _x $ fe $ _2 $在室温应用程序中，长期以来已知$ x $ = 0.73（terfenol-d）。在这里，我们通过计算易于磁化方向和磁截图作为组成和温度的函数来得出此值。我们使用在密度功能理论中获得的晶体场系数来构建现象学各向异性和磁弹性常数。这些常数的温度依赖性是从稀土磁性参数的局部力矩计算中获得的。我们的计算发现，在室温下切换磁化方向所需的关键DY浓度为$ x_c $ = 0.78，带有磁盘$λ_{111} $ = 2700和$λ_{100} $ = -430〜PPM，靠近Terfenol-D值。
The optimal amount of dysprosium in the highly magnetostrictive rare-earth compounds Tb$_{1-x}$Dy$_x$Fe$_2$ for room temperature applications has long been known to be $x$=0.73 (Terfenol-D). Here, we derive this value from first principles by calculating the easy magnetization direction and magnetostriction as a function of composition and temperature. We use crystal field coefficients obtained within density-functional theory to construct phenomenological anisotropy and magnetoelastic constants. The temperature dependence of these constants is obtained from disordered local moment calculations of the rare earth magnetic order parameter. Our calculations find the critical Dy concentration required to switch the magnetization direction at room temperature to be $x_c$=0.78, with magnetostrictions $λ_{111}$=2700 and $λ_{100}$=-430~ppm, close to the Terfenol-D values.
