Magnetic properties of SmFe/sub 3/ and its hydrogenation and nitrogenation

The magnetic properties of hydrogenated or/and nitrogenated SmFe/sub 3/ alloys are studied. It is found that SmFe/sub 3/ can be readily hydrogenated while not nitrogenated. There are two hydrogenation temperatures, that at 195 degrees C corresponding to the formation of SmFe/sub 3/H/sub x/ and that at 450 degrees C corresponding to decrepitation of SmFe/sub 3/ phase forming SmH and alpha -Fe, respectively. The SmFe/sub 3/H/sub 1.34/ has the highest saturation magnetization of all, while anisotropy field decreases due to hydrogenation. The difficulty in nitrogenation is attributed to kinetic reasons of the formation of SmN compound, around 20 nm in size, on the surface or grain boundary of the powder, retarding further diffusion of nitrogen into the matrix.<>