Magnetocaloric properties of a novel ferromagnet Gd3Co4+xAl12-x (x = 0.50).

International audienceA novel gadolinium and cobalt based aluminide, namely Gd3Co4+xAl12-x (x = 0.50(3)) is shown to crystallize in the hexagonal Gd3Ru4Al12 structure-type (space-group P63/mmc, a = 8.6830(1) Å, c = 9.3164(2) Å at room temp.). The investigation of its magnetic properties revealed a reversible ferromagnetic ordering at TC ≈ 40 K but expanding in a wide temp. range, potentially due to the geometrical magnetic frustrations expected in this structure-type. The magnetocaloric properties of this intermetallic, detd. from both magnetization and sp. heat data, are dominated by a max. entropy variation of -3.28 J kg-1 K-1 at 39(1) K and an adiabatic temp. change of about 1.5 K extending from 20 to 40 K, highlighting some interest for low temp. applications