Ruseikina Anna V, Grigoriev Maxim V, Locke Ralf J C, Chernyshev Vladimir A, Garmonov Alexander A, Schleid Thomas
Laboratory of Theory and Optimization of Chemical and Technological Processes, University of Tyumen, Tyumen 625003, Russia.
Institute for Inorganic Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany.
Materials (Basel). 2024 May 11;17(10):2284. doi: 10.3390/ma17102284.
This paper reports for the first time on a new layered magnetic heterometallic erbium telluride EuErCuTe. Single crystals of the compound were obtained from the elements at 1120 K using CsI as a flux. The crystal structure of EuErCuTe was solved in the space group ( = 4.3086(3) Å, = 14.3093(9) Å, and = 11.1957(7) Å) with the KZrCuS structure type. In the orthorhombic structure of erbium telluride, distorted octahedra ([ErTe]) form two-dimensional layers (Er(Te1)2/2e(Te2)4/2k-)∞2, while distorted tetrahedra ([CuTe]) form one-dimensionally connected substructures (Cu(Te1)2/2e(Te2)2/1t5-∞1) along the [100] direction. The distorted octahedra and tetrahedra form parallel two-dimensional layers (CuErTe32-∞2) between which Eu ions are located in a trigonal-prismatic coordination environment (EuTe610-). The trigonal prisms are connected by faces, forming chains (Eu(Te1)2/2(Te2)4/22-∞1) along the [100] direction. Regularities in the variations in structural parameters were established in the series of erbium chalcogenides (EuErCu with = S, Se, and Te) and tellurides (EuCuTe with = Gd, Er, and Lu). Ab-initio calculations of the crystal structure, phonon spectrum, and elastic properties of the compound EuErCuTe were performed. The types and wavenumbers of fundamental modes were determined, and the involvement of ions in the IR and Raman modes was assessed. The experimental Raman spectra were interpreted. The telluride EuErCuTe at temperatures below 4.2 K was ferrimagnetic, as were the sulfide and selenide derivatives (EuErCu with = S and Se). Its experimental magnetic characteristics were close to the calculated ones. The decrease in the magnetic phase transition temperature in the series of the erbium chalcogenides was discovered.
本文首次报道了一种新型层状磁性异金属铒碲化物EuErCuTe。该化合物的单晶通过在1120 K下以CsI为助熔剂由元素合成得到。EuErCuTe的晶体结构在空间群中解析（= 4.3086(3) Å，= 14.3093(9) Å，= 11.1957(7) Å），具有KZrCuS结构类型。在铒碲化物的正交结构中，畸变八面体（[ErTe]）形成二维层（Er(Te1)2/2e(Te2)4/2k -)∞2，而畸变四面体（[CuTe]）沿[100]方向形成一维连接的子结构（Cu(Te1)2/2e(Te2)2/1t5 -∞1）。畸变八面体和四面体形成平行的二维层（CuErTe32 -∞2），Eu离子位于其间的三角棱柱配位环境（EuTe610 -）中。三角棱柱通过面相连，沿[100]方向形成链（Eu(Te1)2/2(Te2)4/22 -∞1）。在铒硫族化物系列（EuErCu，= S、Se和Te）和碲化物系列（EuCuTe，= Gd、Er和Lu）中建立了结构参数变化的规律。对化合物EuErCuTe的晶体结构、声子谱和弹性性质进行了从头算计算。确定了基本模式的类型和波数，并评估了离子在红外和拉曼模式中的参与情况。对实验拉曼光谱进行了解释。碲化物EuErCuTe在低于4.2 K的温度下是亚铁磁性的，其硫化物和硒化物衍生物（EuErCu，= S和Se）也是如此。其实验磁特性与计算值接近。发现了铒硫族化物系列中磁相变温度的降低。
