关于B20-MnSi薄膜的居里温度

On Curie temperature of B20-MnSi films.

作者信息

Li Zichao, Yuan Ye, Begeza Viktor, Rebohle Lars, Helm Manfred, Nielsch Kornelius, Prucnal Slawomir, Zhou Shengqiang

机构信息

Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328, Dresden, Germany.

Institute of Materials Science, Technische Universität Dresden, 01069, Dresden, Germany.

出版信息

Sci Rep. 2022 Sep 30;12(1):16388. doi: 10.1038/s41598-022-20483-2.

DOI:10.1038/s41598-022-20483-2

PMID:36180461

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9525690/

Abstract

B20-type MnSi is the prototype magnetic skyrmion material. Thin films of MnSi show a higher Curie temperature than their bulk counterpart. However, it is not yet clear what mechanism leads to the increase of the Curie temperature. In this work, we grow MnSi films on Si(100) and Si(111) substrates with a broad variation in their structures. By controlling the Mn thickness and annealing parameters, the pure MnSi phase of polycrystalline and textured nature as well as the mixed phase of MnSi and MnSi are obtained. Surprisingly, all these MnSi films show an increased Curie temperature of up to around 43 K. The Curie temperature is likely independent of the structural parameters within our accessibility including the film thickness above a threshold, strain, cell volume and the mixture with MnSi. However, a pronounced phonon softening is observed for all samples, which can tentatively be attributed to slight Mn excess from stoichiometry, leading to the increased Curie temperature.

摘要

B20型MnSi是典型的磁性斯格明子材料。MnSi薄膜的居里温度高于其块状材料。然而，目前尚不清楚是什么机制导致了居里温度的升高。在这项工作中，我们在Si(100)和Si(111)衬底上生长结构差异很大的MnSi薄膜。通过控制Mn厚度和退火参数，获得了多晶和织构性质的纯MnSi相以及MnSi和MnSi的混合相。令人惊讶的是，所有这些MnSi薄膜的居里温度都提高了，最高可达约43K。居里温度可能与我们所能达到的结构参数无关，包括高于阈值的薄膜厚度、应变、晶胞体积以及与MnSi的混合情况。然而，所有样品都观察到明显的声子软化现象，这可能暂时归因于化学计量比中轻微的Mn过量，从而导致居里温度升高。