Influence of hydrogen on the magnetic behaviour of Gd5Ge2Si2Hx, 0.1⩽x⩽2.5

Abstract The influence of hydrogen absorption on T c and M s of the Gd 5 Ge 2 Si 2 H x alloys, with 0.1⩽ x ⩽2.5 was studied by thermomagnetic analysis from 2 to 370 K. The M(T) curves show the first order magnetic transition at 260 K only for the sample with x =0.1. All the samples presented the second-order magnetic transition between 296 ( x =0.1) and 212 K ( x =2.5). For the sample with x ⩾1.2 is also observed a new antiferromagnetic transition at ≈45 K. The M ( H ) curves revealed that the M s tends to increase with the hydrogen amount into the alloy.