Hydrogen resistivity anomaly

The temperature and thickness dependence of the electric resistivity of Sm, Dy and Tm thin films (25-370 nm thick) was measured between 4.2 and 300 K by Dudas and Feher (1984, 1987), Dudas et al. (1985, 1986, 1987a-d, 1990), and Janos et al. (1987). For Dy films the Neel temperature and the residual resistivity ratio increase both as thickness increases. The thickness dependence of the spin-disorder resistivity is reported in fig. 6. In the case of Tm samples it is observed that the Neel temperature increases (from 49 to 54 K) and in-disorder resistivity decreases (from 35 to lOpQm) as thickness increases (fig. 7). Such results, and correlations with the crystalline orientations (basal plane of crystallites parallel or perpendicular to the substrate surface) correct the errors made by other investigators (see Gasgnier 1980). On the other hand the resistance ratio as a fimction of the temperature exhibits different kinds of curves as the thickness varies as measured for Tm films (fig. 8). Different magnetic transitions have been also observed. One can conclude that numerous kinds of anomalies were caused by hydrogen in solution in the metallic matric, in agreement with Dudas (1991), and also by structure... 

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