Low-temperature investigations of the system α-R(H, D)x with R=Er, Tm, Lu after quench and/or electron irradiation

The electrical resistivity of the solid solutions of H in Er, Tm and Lu exhibits an anomaly at -- 160 K. Quenches across the anomaly and subthreshold electron irradiations at liquid helium introduce a Δrho which recovers in one stage in the anomaly region. The observations are interpreted through a ''condensation'' of hydrogen into H-H pairs of lower rho, with a concentration- and isotope mass-dependent binding energy. Quench and irradiation produce isolated H-atoms as defects; upon annealing, they reform into pairs just before the pair dissociation. The H-defects interact with magnetically ordered structures in Er and Tm. (author)