ISSN:
1573-7357
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The variation in the superconducting properties of various binary alloys of the transition metal-germanium system was surveyed by studying sputter-deposited samples prepared under various conditions. Radiofrequency cosputtering was used to form samples of the form T x Ge 1−x , where T represents a transition metal, Y, La, Ti, Zr, Hf, V, Nb, Ta, Mo, W, and Re. The primary interest has been to study the formation of A-15 compounds. While sputtered V 3 Ge hadT cs close to bulk sample values, Nb 3 Ge (T c=21.7 K) and Mo 3 Ge (T c=5.7 K) showed a considerable enhancement inT c over the bulk values. The formation of the metastable A - 15 modification of Ta 3 Ge, Ti 3 Ge, Zr 3 Ge, and Hf 3 Ge was attempted, without success. Superconductivity was observed in samples of ZrGe 2 , HfGe 2 , YGe 2 , and LaGe 2 , the highestT c being that of ZrGe 2 (T c=8.0 K). Annealing studies indicated that superconducting ZrGe2 and HfGe2 were metastable, depending on the conditions of synthesis. Superconductivity was also observed in mixtures of semiconducting Ge and metallic NbGe 2 , the highestT c observed being 16 K. Several explanations are considered to account for the observedT cbehavior among the various alloys.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00655283
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