Superconductivity and specific heat of titanium base A15 alloys

Experimental data on the superconducting transition temperature, and low temperature specific heat, together with X-ray investigations, are reported for binary and pseudo-binary compounds of Ti with the A15-type structure. A 'true' relative maximum of the coefficient of the electronic specific heat, γ, as well as the superconducting transition temperature, Tsub(c), occurs in the Tisub(3)Irsub(1-x)Ptsub(x) system near x = 0.2. Tisub(3)Irsub(0.8)Ptsub(0.2) shows the lowest Debye temperature, theta0, of all A15-type compounds known to date. The anomalous temperature dependence of the lattice specific heat may be reproduced by a model phonon spectrum similar to that of Nb3Sn. (author)