pISSN 0374-4914 eISSN 2289-0041

## Research Paper

New Phys.: Sae Mulli 2018; 68: 829-833

Published online August 31, 2018 https://doi.org/10.3938/NPSM.68.829

## Effects of Maganese Impurity on the Crystallographic and Spin-Rotation Transitions in FeS

Engchan KIM*

Department of Physics, Yeungnam University, Gyongsan 38541, Korea

Correspondence to:eckim@yu.ac.kr

Received: May 25, 2018; Revised: July 4, 2018; Accepted: July 10, 2018

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

### Abstract

The effects of manganese ions on the crystallographic and the spin-rotation transitions in iron sulfide have been examined by using Mössbauer spectroscopy in the temperature ranging from 78 to 600 K. The manganese impurity of Mn$_{0.02}$Fe$_{0.98}$S is noted to affect both the crystallographic and spin-rotation transitions in the iron sulfide. The impurity of 2% of Mn$^{2+}$ in FeS causes an increase in the separation between the spin rotation and the $\alpha$ transition temperatures by as much as 20 K compared with that for FeS without the impurity. Both the 1c and the 2c structures coexist in the temperature range between the $\alpha$ transition temperature and approximately 27 K, with a smaller hyperfine field corresponding to the 1c structure. The spin-rotation temperature for Mn$_{0.02}$Fe$_{0.98}$S was measured as 366 K, which is 22 K lower than the $\alpha$ transition temperature. For a 2% impurity of Mn$^{2+}$ in FeS, the Néel temperature is not appreciably affected.

Keywords: Spin-rotation transition, $\alpha$ transition, Mössbauer spectroscopy, FeS