Measurement of pressure effects on the magnetic and the magnetocaloric properties of the intermetallic compounds R(Co1-xSix)2 [R=Dy and Er]

TL;DR

This study investigates how external pressure influences the magnetic and magnetocaloric properties of R(Co1-xSix)2 compounds, revealing pressure-dependent changes in transition temperatures, critical fields, and entropy changes, especially in Si-substituted variants.

Contribution

It provides new insights into pressure effects on magnetocaloric properties and the role of spin fluctuations and magnetovolume effects in these intermetallic compounds.

Findings

Transition temperatures decrease with pressure.

Magnetocaloric effect is enhanced in Si substituted compounds under pressure.

Critical field for metamagnetic transition increases with pressure.

Abstract

The effect of external pressure on the magnetic properties and magnetocaloric effect of R(Co1-xSix)2 [R= Er, Dy and x=0, 0.025 and 0.05] compounds has been studied. The ordering temperatures of both the parent as well as the Si substituted compounds are found to decrease with pressure. In all the compounds, the critical field for metamagnetic transition increases with pressure. It is seen that the magnetocaloric effect in the parent compounds is almost insensitive to pressure, while there is considerable enhancement in the case of Si substituted compounds. Spin fluctuations arising due to the magnetovolume effect play a crucial role in determining the pressure dependence of magnetocaloric effect in these compounds. Analysis of the magnetization data using the Landau theory has shown that the magnitude of the Landau coefficient (C3) decreases with Si concentration whereas it is found to increase with pressure. The isothermal magnetic entropy change is found to behave in the same manner as C3, both with Si concentration (at ambient pressure) as well as with the applied pressure.