Strongly enhanced magnetic moments in ferromagnetic FeMnP$_{0.50}$Si$_{0.50}$

TL;DR

This study investigates FeMnP$_{0.50}$Si$_{0.50}$, revealing unexpectedly high magnetic moments and hyperfine fields, with potential for magnetocaloric applications due to its tunable transition temperature.

Contribution

The paper reports the discovery of significantly enhanced magnetic moments in FeMnP$_{0.50}$Si$_{0.50}$ and links experimental results with electronic structure calculations, highlighting its potential for magnetic cooling.

Findings

High magnetic hyperfine field for Fe atoms at tetrahedral sites.

Saturation magnetic moment of 4.4 μ_B per formula unit.

First order ferromagnetic transition with tunable temperature.

Abstract

The compound FeMnP$_{0.50}$Si$_{0.50}$ has been studied by magnetic measurements, M\"ossbauer spectroscopy and electronic structure and total energy calculations. An unexpected high magnetic hyperfine field for Fe atoms located at the tetrahedral Me(1) site in the Fe$_2$P structure is found. The saturation moment derived from magnetic measurements corresponds to 4.4 $\mu_B$/f.u. at low temperatures, a value substantially higher than previously reported, but in accord with the results from our electron structure calculations. This high saturation moment, a first order nature of the ferromagnetic transition and a tunable transition temperature make the Fe$_{2-x}$Mn$_{x}$P$_{1-y}$Si$y$ system promising for magnetocaloric applications.