Magnetocaloric properties of Fe_{2-x}T_xP (T = Ru and Rh) from electronic structure calculations and magnetisation measurements

TL;DR

This study combines electronic structure calculations and magnetisation measurements to analyze the magnetocaloric properties of Fe2P and its Ru and Rh substituted variants, revealing insights into their magnetic entropy and behavior above Curie temperature.

Contribution

It introduces a combined computational and experimental approach to understand the magnetocaloric effects in Fe2P-based compounds, including the impact of substitution and paramagnetic states.

Findings

Electronic and magnetic entropies agree with experimental data.

Fe magnetic moments vary between sites in the paramagnetic state.

Substitutions influence magnetic properties and entropy values.

Abstract

An analysis of the magnetocaloric properties of the pure and substituted Fe2P compounds is made based on KKR-CPA electronic structure calculations and magnetisation M(H,T) measurements. The computed electronic densities of states and magnetic moments are used to calculate both the values of the electronic and magnetic entropies, which fairly agree with the experimental findings. To enlighten the magnetic properties above Curie temperature, the paramagnetic state behaviours are simulated using the disordered local moments (DLM) concept. The KKR-CPA computations show, that in Fe2P, the Fe magnetic moment of the (3f) site disappears in the DLM state, while the moment of the (3g) site is only little lowered, comparison made with the low temperature ferromagnetic state.