论文标题
部分可观测时空混沌系统的无模型预测
First principles investigations of the electronic and magnetic properties of RVO3 (R = Er, Ho, Y, Lu) vanadates
论文作者
论文摘要
在本文中，我们研究了稀土元件（R）对RVO3物理特性（R = ER，HO，Y，LU）的影响。为此，在本研究中使用AB ITIOL方法报告了理论工作，以增强我们对RVO3（R = ER，HO，HO，Y，LU）化合物的电子和磁性的了解。这些材料的电子特性显示了Jahn-Teller效应的存在，对于ERVO3，HOVO3，YVO3，LUVO3，带隙分别为0.58EV，1.57EV，1.12EV，1.28EV。 HOVO3中HO，ER和V原子的磁性贡献，以及ERVO3化合物使用X射线磁性圆形二色性（XMCD）散布。使用旋转轨道偶联对具有（r = er，ho，y，lu）的RVO3的磁各向异性进行了研究和分析。我们注意到沿C方向易于磁化的轴，该磁化强度具有较强的磁性晶状体各向异性能量，用于非磁性稀土元件（r = lu，y）vo3。对于磁性稀土元素，发现易于且硬化的方向沿B轴和C轴，以及Hovo3和Ervo3的A轴和C轴。这意味着，代替标准的磁化消电过程，可以通过在恒定磁场中旋转其单晶来获得巨大的热效应。还发现（HO-V）之间的交换耦合大于HOVO3中的其他交换相互作用。因此，由于Ho Ising时刻经历了元磁过渡，因此可以在Hovo3中产生大型常规磁性效应。然而，由于弱（ER-V）交换耦合，预计ERVO3中的磁电效应（MCE）将较低。
In this paper, we investigate the influence of the rare earth element (R) on the physical properties of RVO3 (R = Er, Ho, Y, Lu). For this purpose, a theoretical work is reported in this study using ab initio method with the intent of enhancing our knowledge of the electronic, and magnetic properties of RVO3 (R = Er, Ho, Y, Lu) compounds. The electronic properties of these materials show the presence of Jahn-Teller effect, with a band gap of approximately 0.58eV, 1.57eV, 1.12eV, 1.28eV, for ErVO3, HoVO3, YVO3, LuVO3, respectively. The magnetic contribution of Ho, Er, and V atoms in HoVO3, and ErVO3 compounds was disentangled using X-ray magnetic circular dichroism (XMCD). The magnetic anisotropies of RVO3 with (R = Er, Ho, Y, Lu) are studied and analyzed using spin orbit coupling. We noticed an easy axis of magnetization along the c-direction with strong magneto-crystalline anisotropy energies for the non-magnetic rare earth elements (R = Lu, Y)VO3. For the magnetic rare earth elements, the easy and hard magnetization direction were found to be along b-axis and c-axis, and a- axis and c-axis for HoVO3, and ErVO3, respectively. This means that instead of the standard magnetization demagnetization process, large thermal effects can be obtained by spinning their single crystals in constant magnetic fields. The exchange coupling between (Ho-V) is also found to be greater than the other exchange interactions in HoVO3. Accordingly, a large conventional magnetocaloric effect could be created in HoVO3, since the Ho Ising moments experience a metamagnetic transition. However, the magnetocaloric effect (MCE) is expected to be lower in ErVO3 due to the weak (Er-V) exchange coupling.
