Superconducting transition temperatures of amorphous binary alloy systems based on Bi,Pb, Ga and Be

Quench condensed binary alloy films are produced by evaporation from two separated furnaces. The films contain the whole composition range of the respective alloy system in well defined arrangement.T _c is measured as a function of concentration. Eight predominantly amorphous alloy systems are studied: Bi—Ga, Pb—Ga, Pb—Bi, Be—Bi, Be—Pb, Be—Ga, Be—Al, Be—Li. In Bi—Ga and Pb—GaT _c is a linear function of concentration in the amorphous composition range. In Pb—BiT _c has a maximum. All Be-alloys show lower transition temperatures than pure quench condensed Be. Except for Be—Li all systems have aT _c minimum. The experiments are compared to aT _c calculation using tunelling spectroscopy data. Except for the Be-alloys the agreement is satisfying.