Multifunctional behavior of Mn-site doped antiferromagnetic Mn$_5$Si$_3$ alloys

TL;DR

This study explores how doping Mn$_5$Si$_3$ alloys with Ni and Cr affects their magnetoresistance and magnetocaloric properties, revealing complex behaviors useful for magnetic cooling and sensor applications.

Contribution

It provides a detailed analysis of the effects of Ni and Cr doping on the magnetoresistance and magnetocaloric effects in Mn$_5$Si$_3$ alloys, highlighting new insights into their multifunctional behavior.

Findings

Doping decreases magnetoresistance monotonically.

Inverse MCE decreases with increased doping.

Conventional MCE significantly increases with doping.

Abstract

Present work reports a detailed investigation on the magnetoresistance and magnetocaloric behavior of Ni and Cr-doped Mn$_5$Si$_3$ alloys with general formula Mn$_{5-x}$A$_x$Si$_3$ (where A = Ni/Cr; $x$ = 0, 0.05, 0.1 and 0.2). Both pure (undoped) and doped alloys show a reasonably large amount of magnetoresistance (MR). Doping at Mn-site, both by Ni and Cr, results in a monotonic decrease in MR values. Magnetocaloric effect (MCE), on the other hand, is found to be interesting, and all the alloys show both conventional and inverse MCE around the magneto-structural transition temperature. Among the two types of MCE observed, the inverse MCE is found to decrease with increasing doping concentration and consistent with the MR behavior, whereas doping results in a significant increase in conventional MCE values.