Department of Chemistry, The City College of New York, New York, NY, 10031, USA.
Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.
Sci Rep. 2023 May 6;13(1):7381. doi: 10.1038/s41598-023-34585-y.
Magnetic topological materials are promising for realizing novel quantum physical phenomena. Among these, bulk Mn-rich MnSbTe is ferromagnetic due to Mn antisites and has relatively high Curie temperatures (T), which is attractive for technological applications. We have previously reported the growth of materials with the formula (SbTe)(MnSbTe), where x varies between 0 and 1. Here we report on their magnetic and transport properties. We show that the samples are divided into three groups based on the value of x (or the percent septuple layers within the crystals) and their corresponding T values. Samples that contain x < 0.7 or x > 0.9 have a single T value of 15-20 K and 20-30 K, respectively, while samples with 0.7 < x < 0.8 exhibit two T values, one (T) at ~ 25 K and the second (T) reaching values above 80 K, almost twice as high as any reported value to date for these types of materials. Structural analysis shows that samples with 0.7 < x < 0.8 have large regions of only SLs, while other regions have isolated QLs embedded within the SL lattice. We propose that the SL regions give rise to a T of ~ 20 to 30 K, and regions with isolated QLs are responsible for the higher T values. Our results have important implications for the design of magnetic topological materials having enhanced properties.
磁性拓扑材料在实现新的量子物理现象方面具有广阔的前景。其中，富锰 MnSbTe 由于 Mn 反位和较高的居里温度 (T) 而具有铁磁性，这对于技术应用具有吸引力。我们之前曾报道过具有化学式 (SbTe)(MnSbTe) 的材料的生长，其中 x 的取值范围在 0 到 1 之间。在此，我们报告了它们的磁性和输运性质。我们发现，根据 x 的值（或晶体中七重层的百分比）及其对应的 T 值，样品可分为三组。x<0.7 或 x>0.9 的样品分别具有 15-20 K 和 20-30 K 的单一 T 值，而 0.7<x<0.8 的样品则具有两个 T 值，一个在~25 K 左右（T），第二个 T 值达到 80 K 以上，几乎是迄今为止报道的此类材料的两倍。结构分析表明，0.7<x<0.8 的样品具有较大的仅由 SL 组成的区域，而其他区域则具有嵌入 SL 晶格中的孤立的 QL。我们提出 SL 区域产生了约 20 到 30 K 的 T 值，而具有孤立的 QL 的区域则负责更高的 T 值。我们的结果对具有增强性能的磁性拓扑材料的设计具有重要意义。
