Crystal structure, magnetism and magnetocaloric properties of Mn_2−xSn_0.5Ga_0.5 (x=0, 0.3, 0.5, 0.8) alloys

Authors

H. Qian, Changzhou University
Rabindra Pahari, University of Nebraska - LincolnFollow
K. Schroeder, South Dakota State University
Shah R. Valloppilly, University of Nebraska-LincolnFollow
Y. Huh, South Dakota State University
Pavel V. Lukashev, University of Nothern IowaFollow
J. Hu, Changzhou University
Parashu Kharel, South Dakota State University, University of Nebraska-LincolnFollow
David J. Sellmyer, Nebraska Center for Materials and NanoscienceFollow

Date of this Version

2019

Citation

Published in Journal of Magnetism and Magnetic Materials 471 (2019), pp 411–415

doi:10.1016/j.jmmm.2018.09.123

Comments

Copyright © 2018 Elsevier B.V. Used by permission.

Abstract

Magnetic refrigeration based on the magnetocaloric effect has attracted recent attention due to advantages such as high efficiency and environmental friendliness. We have investigated the structural, magnetic and magnetocaloric properties of Mn_2−xSn_0.5Ga_0.5 (x=0, 0.3, 0.5, 0.8) alloys prepared using arc-melting and meltspinning techniques with prospects for magnetic refrigeration. The Mn_2−xSn_0.5Ga_0.5 alloys, except for Mn_1.2Sn_0.5Ga_0.5, have a single-phase hexagonal crystal structure. The Mn_1.2Sn_0.5Ga_0.5 alloy also contains a small amount of MnSn₂ impurity phase. The Curie temperature and high-field (30 kOe) magnetization at 55 K decrease with increasing Mn concentration from 306 K and 64.1 emu/g (1.07 μ_B/Mn) for Mn_1.2Sn_0.5Ga_0.5 to 262 K and 46.7 emu/g (0.85 μ_B/Mn) for Mn₂Sn_0.5Ga_0.5, respectively. The peak values of magnetic entropy change are relatively small with ΔS_M,max=1.7 Jkg⁻¹K⁻¹for Mn_1.5Sn_0.5Ga_0.5 at 30 kOe. Despite this, these materials show considerable relative cooling power (RCP) along with a wide working temperature range near room temperature and negligible magnetic and thermal hysteresis, where Mn_1.2Sn_0.5Ga_0.5 shows a highest RCP of 102.3 Jkg^₋₁ at 30 kOe.