Unveiling the Structural, Electronic and Magnetic Properties of GdASiO (A = K, Na, and Li) Oxides With Promising Potential for Low-Temperature Magnetic Cooling.

The growing demand for solid-state magnetic cooling, leveraging the magnetocaloric effect requires the discovery of high-performing magnetocaloric materials (MCMs). Herein, a family of Gd-containing MCMs is provided, specifically the GdASiO (A = K, Na, and Li) oxides, which demonstratse exceptional low-temperature magnetocaloric performance. Through comprehensive experimental investigations and theoretical calculations on their structural, electronic, and magnetic properties, it is unequivocally confirmed that all of them crystallize in a hexagonal apatite-type structure (space group P6/m), exhibiting an antiferromagnetic semiconductor ground state with magnetic ordering temperatures below 1.