Investigation of the structure, magnetic properties, and magnetocaloric effect of Gd2WO6 compound

Abstract

Developing novel magnetic materials that combine large magnetic-entropy changes with low magnetic-ordering temperatures is a central challenge for improving refrigeration efficiency in the very-low-temperature and sub-Kelvin regimes. Here, we report the synthesis of Gd2WO6, a gadolinium-based tungstate that crystallizes in a orthorhombic structure (space group P212121), and presents a systematic study of its crystal structure, magnetic phase behavior, and low-temperature magnetocaloric properties. Gd3+ ions, with S = 7/2 and L ≈ 0, possess a large spin ground state and negligible orbital contribution, resulting in weak crystal-field effects and making them favorable carriers of large magnetocaloric responses at low temperatures. Powder x-ray diffraction confirms the orthorhombic P212121 structure. Magnetic measurements indicate magnetic ordering below 2 K, and a pronounced magnetocaloric effect: the maximum magnetic-entropy change reaches 34.8 J/kg K for a field change of 0–7 T. These results identify Gd2WO6 as a promising host material for applications in very-low-temperature magnetic refrigeration and as a candidate for further exploration toward sub-Kelvin cooling.