The effect of hydrogenation on the crystal structure and magnetic state in Pd3Mn

Abstract The effect of hydrogenation on the crystal structure and magnetic state of Pd 3 Mn has been calculated using a full-potential linear augmented plane wave method in the local spin density approximation.When hydrogenated the system is observed to transform from the tetragonal Al 3 Zr structure to the cubic Cu 3 Au structure. When hydrogen is removed the system remains in a meta-stable cubic phase for an extended period of time. The structural transformations are associated with a change in the magnetic state. Our theoretical results of magnetic as well as crystal structure stability are in agreement with experiments, especially the destabilization of the tetragonal structure for increased hydrogen concentration and complex magnetic structure of the cubic phases. The latter is analyzed in terms of Fermi surface nesting.