论文标题
$ \ textit {ab initio} $旋转玻璃pyrochlore nasrmn $ _ {2} $ f $ _ {7} $的磁性属性描述
$\textit{Ab initio}$ description of magnetic properties of spin-glass pyrochlore NaSrMn$_{2}$F$_{7}$
论文作者
论文摘要
在这项研究中，我研究了锰pyrochlore氟化物NASRMN $ _ {2} $ f $ _ {7} $的磁性和关键特性，该$ _ {7} $，由于电荷障碍而在T $ _ \ text {f} $ _ \ text {f} $ _ \ text {f} $ _ \ text {f} $ 2.5（k）上表现出玻璃过渡。本文使用DFT+$ u $+SOC框架来推导自旋 - 哈米尔顿术语，包括各向同性和各向异性交换相互作用。优化的几何形状揭示了沿$ <$ 111 $> $方向的F-MN-F角度的局部变形（95.48 $^{\ circ} $和84.51 $^{\ circ} $），这被认为是弱债券障碍（$ΔJJ$）。尽管有这种材料的复杂结构，但第一个原理计算表明，其磁性仅由最近的邻居的海森堡交换相互作用控制，而其他相互作用不会影响基态下的旋转布置。因此，该材料被认为是研究自旋玻璃中电子相关性的合适候选者。使用复制 - 交换框架，蒙特卡洛模拟表明，当磁敏感性随温度变化时，未观察到相变。基于$ΔJ$和自旋哈密顿量，获得2.6（k）作为相变温度。
In this study, I have investigated the magnetic and critical properties of manganese pyrochlore fluoride NaSrMn$_{2}$F$_{7}$, which exhibits a glass transition at T$_\text{f}$$=$2.5 (K) due to charge disorder. A DFT+$U$+SOC framework is used in this paper to derive spin-Hamiltonian terms, including isotropic and anisotropic exchange interactions. An optimized geometry reveals a local distortion of the F-Mn-F angle along the $ < $111$ > $ direction (95.48$^{\circ}$ and 84.51$^{\circ}$), which is considered a weak bond disorder ($δJ$). In spite of the complex structure of this material, first principle calculations show that its magnetic properties are only controlled by the nearest neighbor's Heisenberg exchange interaction, and other interactions do not affect spin arrangements in the ground state. Thus, this material is considered a suitable candidate for studying electron correlation in spin glasses. Using a replica-exchange framework, Monte Carlo simulations indicate that no phase transition is observed when magnetic susceptibility changes with temperature. Based on $δJ$ and the spin Hamiltonian, 2.6 (K) is obtained as the phase transition temperature.
