Localization effects and Anomalous Hall conductivity in a disordered 3D ferromagnet

Authors

Paul M. Shand, University of Northern IowaFollow
Y. Moua, University of Northern Iowa
G. Baker, South Dakota State University
Shah R. Valloppilly, University of Nebraska-LincolnFollow
Pavel V. Lukashev, University of Nothern IowaFollow
Parashu Kharel, South Dakota State UniversityFollow

Date of this Version

2022

Citation

Published (2022) in Journal of Magnetism and Magnetic Materials, 563, art. no. 170035

DOI: 10.1016/j.jmmm.2022.170035

Comments

Copyright © Elsevier. Used by permission.

Abstract

We have prepared the Heusler alloy CoFeV_0.5Mn_0.5Si in bulk form via arc melting. CoFeV_0.5Mn_0.5Si is ferromagnetic with a Curie temperature of 657 K. The longitudinal resistivity exhibits a minimum at 150 K, which is attributable to competition between quantum interference corrections at low temperatures and inelastic scattering at higher temperatures. The magnetoresistance (MR) is positive and nearly linear at low temperatures and becomes negative at temperatures close to room temperature. The positive MR in the quantum correction regime is evidence of the presence of the enhanced electron interaction as a contributor to the longitudinal resistivity. Hall effect measurements indicate a carrier concentration of the order of 10₂₂ cm^-3, which is nearly 3 orders of magnitude higher than that found in the “parent” material CoFeMnSi. The higher carrier concentration is consistent with the predicted half metallicity of CoFeV_0.5Mn_0.5Si. The anomalous Hall conductivity of CoFeV_0.5Mn_0.5Si is temperature independent for temperatures below the resistivity minimum, which is strong evidence of the absence of quantum interference effects on the anomalous Hall conductivity in a 3D ferromagnet.