Abstract
Specific heat measurements have been made on splat-cooled La.84Ga.16, La.80Ga.20, La.76Ga.24, La.74Ga.26, La.72Ga.28, La.80Au.20, and La.76Au.24 amorphous alloys in the temperature range 1.3 to 6k. Debye temperatures calculated are approximately 100k for the La1-xAux alloys and approximately 115k for the La1-xGax alloys. Electron-phonon coupling constants and electronic density of states calculated from the data show that these alloys are fundamentally different from the amorphous non-transition metal alloy systems of Ga, Sn, In, Bi, and Pb. The most striking feature is that the amorphous transition metals appear to be weak to intermediate-coupling superconductors in contrast to the very strong-coupling simple amorphous metals. Furthermore, in contrast to many of the simple amorphous metals and liquid metals, the free electron model appears to be totally inadequate for the description of the electronic structure of the amorphous transition metals. In addition to the bulk amorphous or fine-crystalline phase a second superconducting transition near 2k which appears to be associated with few percent of a different, presumably crystalline, phase is observed for many of these samples.
Shull, William Holcomb (1977). Specific heats of amorphous "splat-cooled" La [subscript 1-x] Au [subscript x] and La [subscript 1-x] Ga [subscript x] alloys. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -372317.