ε → δ phase transition in TiH0.71 hydride: superconductivity and resistivity

Different intermediate states during ε → δ irreversible transformation of TiH0.71 were obtained through a series of low-temperature annealings. Temperatures of superconducting transitions Tc and resistance temperature dependences in the normal state p(t)=PO+PT, where PO - is residual resistance, PT - temperature-dependingpart, were measured in these states for TiH0.71. Characteristic type of dependence Tc on pO allows to suggest the presence of several stages in transformation. Within Tc<T<or approx.50 K range, when all the processes of structure irreversible transformations are frozen, pT dependences are well approximated by AT2+BT3 functions. During ε → δ transformation A coefficients reduce from +0.3x10-3 up to 0.13x10-3 mcOhmxcm/k2, while B coefficients remain approximately constant, equal to +0.014x10-3 mcOxcm/k3