Collinear antiferromagnetism in trigonal SrMn$_{2}$As$_{2}$ revealed by single-crystal neutron diffraction
| Autor: | Das, Pinaki, Sangeetha, N. S., Pandey, Abhishek, Benson, Zackery A., Heitmann, T. W., Johnston, D. C., Goldman, A. I., Kreyssig, A. |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | J. Phys.: Condens. Matter 29, 035802 (2017); 5 pages |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0953-8984/29/3/035802 |
| Popis: | Fe pnictides and related materials have been a topic of intense research for understanding the complex interplay between magnetism and superconductivity. Here we report on the magnetic structure of SrMn$_{2}$As$_{2}$ that crystallizes in a trigonal structure ($P\bar{3}m1$) and undergoes an antiferromagnetic (AFM) transition at $T_{\textrm c}$ $= 118(2)$ K. The magnetic susceptibility remains nearly constant at temperatures $T \le T_{\textrm N}$ with $\textbf{H}\parallel \textbf{c}$ whereas it decreases significantly with $\textbf{H}\parallel \textbf{ab}$. This shows that the ordered Mn moments lie in the $\textbf{ab}$-plane instead of aligning along the $\textbf{c}$-axis as in tetragonal BaMn$_{2}$As$_{2}$. Single-crystal neutron diffraction measurements on SrMn$_{2}$As$_{2}$ demonstrate that the Mn moments are ordered in a collinear N\'{e}el AFM phase with $180^\circ$ AFM alignment between a moment and all nearest neighbor moments in the basal plane and also perpendicular to it. Moreover, quasi-two-dimensional AFM order is manifested in SrMn$_{2}$As$_{2}$ as evident from the temperature dependence of the order parameter. Comment: 5 pages, 3 figures |
| Databáze: | arXiv |
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