Structure, magnetism, and electron-transport properties of Mn₂CrGa-based nanomaterials

Authors

Wenyong Zhang, University of Nebraska-LincolnFollow
Parashu Kharel, University of Nebraska-LincolnFollow
Ralph Skomski, University of Nebraska-LincolnFollow
Shah R. Valloppilly, University of Nebraska-LincolnFollow
XINGZHONG LI, Nebraska Center for Materials and NanoscienceFollow
David J. Sellmyer, University of Nebraska-LincolnFollow

Date of this Version

2016

Citation

AIP ADVANCES 6, 056218 (2016)

http://dx.doi.org/10.1063/1.4944403

Comments

Copyright 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

Abstract

Mn₂CrGa in the disordered cubic structure has been synthesized using rapid quenching and subsequent annealing. The cubic phase transforms to a stable tetragonal phase when a fraction of Cr or Ga is replaced by Pt or Al, respectively. All samples are ferrimagnetic with high Curie temperatures (T_c); Mn₂CrGa exhibits the highest Tc of about 813 K. The tetragonal samples have appreciable values of magnetocrystalline anisotropy energy, which leads to an increase in coercivity (H_c) that approaches about 10 kOe in the Pt-doped sample. The Hc linearly increases with a decrease of temperature, concomitant with the anisotropy change with temperature. All samples are metallic and show negative magnetoresistance with room-temperature resistivities on the order of 1 mΩcm. The magnetic properties including high T_c and low magnetic moment suggest that these tetragonal materials have potential for spin-transfertorque- based devices.