Magnetism of Mn, Fe, Co Impurities in PdH_x as a Function of Hydrogen Concentration; Relation with the Electronic Structure of the Host

Abstract

We present experimental data concerning the magnetic ordering temperature T_c of PdH_x compounds containing small amounts of magnetic impurities M (= Mn, Fe, Co). We consider the case x = 0 and the entire homogeneous β phase with 0,6. ≤ x ≤ 1. We show that the interactions are strongly reduced if one goes from the x = 0 case to the β phase. Most of the trends concerning the changes of T_c with x are explained by variation of the Fermi level conduction electrons and of the Stoner exchange enhancement factor of the host conduction electrons.