Experimental and theoretical investigations on magnetic and related properties of ErRuSi

TL;DR

This study combines experimental and theoretical methods to analyze the magnetic, optical, and magnetocaloric properties of ErRuSi, revealing ferromagnetic order, significant magnetocaloric effects, and electronic structure insights relevant for low-temperature magnetic refrigeration.

Contribution

It provides a comprehensive investigation of ErRuSi using multiple techniques, highlighting its potential for magnetic refrigeration and elucidating its electronic and magnetic structure.

Findings

Ferromagnetic ordering with moments in ab plane

Large magnetocaloric effect with 4.7 K temperature change

Significant negative magnetoresistance at low temperatures

Abstract

We report experimental and theoretical studies of magnetic and related properties of ErRuSi compound. Various experimental techniques such as neutron diffraction, magnetization, magneto-thermal, magneto-transport, optical have been used to study the compound. Neutron diffraction shows ferromagnetic ordering at low temperatures with moments aligned in ab plane. Neutron diffraction and magnetization data show reduction in magnetic moment, which may be due to crystalline electric field effects at low temperatures. The compound shows good magnetocaloric properties with a low field adiabatic temperature change of 4.7 K, which is larger than that of many proposed materials for magnetic refrigeration at low temperatures. Magnetoresistance shows large negative value at 8 K, which changes its sign and increases in magnitude, with decrease in temperature and/or increase in field. The positive MR at low temperatures attributed to the Lorentz force effect. The electronic structure calculations accounting for electronic correlations of the 4f electrons of Er reproduces the ferromagnetic ordering and effective magnetic moment. Interband transitions between the Ru and Er d states and Er f states in one spin projection are found to form the main features of the measured optical conductivity in this compound.