Magnetic and magnetocaloric properties of Gd1-xYx2NiSi3 compounds (x = 0.25, 0.5, 0.75)

Abstract

Abstract In this work, we report the magnetic dilution effect on the magnetic and magnetocaloric properties of Gd 1 - x Y x 2 NiSi 3 (x = 0.25, 0.5, 0.75) compounds by partial substitution of Y ions in Gd 2 NiSi 3 . The X-ray diffraction studies indicate all theses compounds form in AlB 2 type hexagonal crystal structure. The dc magnetic measurements reveal the compounds undergo antiferromagnetic like phase transition below 11.5, 7.2, and 3.1 K for x = 0.25, 0.5 and 0.75 compositions, respectively. The magnetic ground state of the compounds becoming increasingly fragile with the increase in Y concentration, and results in magnetic field induced ferromagnetic transition. Such change in magnetic spin configuration is responsible for moderately large magnetic entropy change ( Δ S M ∼ 19.3 J/kg-K, 14.8 J/kg-K and 9.8 J/kg-K for x = 0.25, 0.5, and 0.75, respectively, for Δ H = 7 T) in the cryogenic temperature region. The relative cooling power (RCP) has also been estimated for all the compounds that appears to be modest ( ∼ 503 J/kg for 7 T magnetic field change) for x = 0.25 analogue and reduces further with magnetic dilution effect caused by Y substitution.