Location of deuterium and its interaction with magnetic order in HCP thulium: a neutron diffraction study

A neutron diffraction investigation of Tm and its solid solutions with D, alpha TmD 0.06 and alpha TmD 0.09 , has permitted the tetrahedral interstitialcy to be determined as the preferential site for D occupation at room temperature, at 60K and at 4.2K. The analysis of the magnetic lines appearing at low temperatures yielded the magnetic moment, m and the Neel temperature, T N , of the samples indicating a regular decrease of both m and T N with increasing D content. The results are explained in terms of a depopulation of metallic d bands, decreasing the number of conduction electrons responsible for the RKKY exchange interaction.