标题： XRD 对掺杂螺旋磁体 CuGaCr$_{4}$S$_{8}$中高于 40 T 的磁化平台的研究 显示英文标题

标题： XRD study of the magnetization plateau above 40 T in the frustrated helimagnet CuGaCr$_{4}$S$_{8}$

摘要： CuGaCr$_{4}$S$_{8}$，其中包含一种铬呼吸型钙钛矿网络，表现出多种磁相，包括低于31 K的非共线螺旋态以及高于40 T的1/2磁化平台，这是由于磁挫与自旋-晶格耦合之间的相互作用所致。 在这里，我们在55 T的脉冲高磁场下对CuGaCr$_{4}$S$_{8}$进行了单次粉末X射线衍射实验，在低温下进入1/2磁化平台相时，揭示了正交相到立方相（或伪立方相）的结构转变。 这一观察结果表明出现了一种共线铁磁序，其中每个小四面体实现了3上1下的自旋构型，每个大四面体则为全上或全下。 我们提出了两种16亚晶格磁结构，它们在第一、第二和第三近邻之间的交换相互作用中是简并的。 显示英文摘要

摘要： CuGaCr$_{4}$S$_{8}$, which contains a chromium breathing pyrochlore network, exhibits diverse magnetic phases, including an incommensurate helical state below 31 K and a 1/2-magnetization plateau above 40 T, owing to the interplay between magnetic frustration and spin-lattice coupling. Here, we perform a single-shot powder x-ray diffraction experiment on CuGaCr$_{4}$S$_{8}$ in a pulsed high magnetic field of 55 T, revealing an orthorhombic-to-cubic (or pseudocubic) structural transition upon entering the 1/2-magnetization plateau phase at low temperatures. This observation suggests the emergence of a commensurate ferrimagnetic order, where a 3-up-1-down spin configuration is realized in each small tetrahedron, and the all-up or all-down in each large tetrahedron. We propose two types of 16-sublattice magnetic structures, which are degenerate within exchange interactions between the first, second, and third nearest neighbors.