论文标题
Cov $ _2 $ o $ $ _4 $的薄膜中的大型磁各向异性和磁截图
Large Magnetic Anisotropy and Magnetostriction in Thin Films of CoV$_2$O$_4$
论文作者
论文摘要
在（001）Srtio $ _3 $底物上，尖晶石钴钒酸盐cov $ _2 $ o $ _4 $。使用扭矩磁力测定实验，我们发现先前观察到的温度诱导的各向异性变化，其中易于轴从平面的偏离[001]方向变化为具有平面<100>易于轴的双轴各向异性，发生在逐渐的二阶结构相变。这项工作表征了（001），（100）和（-110）旋转平面中的这种过渡和磁各向异性，并探索其场依赖性最高30〜t。低于80〜K，滞后特征出现在硬轴周围，即（-110）和（010）旋转中的平面外向以及（001）旋转中的平面<110>方向。这是由于Zeeman能量源自磁化磁场的滞后滞后，随着样品的旋转。磁滞的出现持续到很高的场，表明低温下的各向异性相当强。另外，在增加的施加场中，扭矩响应对称性的场依赖性扭曲表明，磁盘在确定各向异性的方向和幅度方面起着很大的作用。
Spinel Cobalt Vanadate CoV$_2$O$_4$ has been grown on (001) SrTiO$_3$ substrates. Using torque magnetometry experiments, we find that the previously observed temperature induced anisotropy change, where the easy axis changes from the out of plane [001] direction to a biaxial anisotropy with planar <100> easy axes, occurs in a gradual second-order structural phase transition. This work characterizes this transition and the magnetic anisotropies in the (001), (100), and (-110) rotation planes, and explores their field dependence up to 30~T. Below 80~K, hysteretic features appear around the hard axes, i.e., the out-of-plane direction in (-110) and (010) rotations and the planar <110> directions in (001) rotations. This is due to a Zeeman Energy that originates from the lag of the magnetization with respect to the applied magnetic field as the sample is rotated. The appearance of the hysteresis, which persist up to very high fields, shows that the anisotropy at low temperature is rather strong. Additionally, field dependent distortions to the symmetry of the torque response in increasing applied fields shows that magnetostriction plays a large role in determining the direction and magnitude of the anisotropy.
