@article{516d1943bf2e4e358ba609ede0361d11,
title = "High pressure induced shifts in the superconducting transition temperature of sputtered films",
abstract = "Both negative and positive shifts in the superconducting transition temperature with negligibly small changes in the resistance ratio were observed in the NbGe and V3Si films, respectively, under pressure up to ∼ 22 kbar. The results are discussed along with the roles of defects recently proposed in these materials.",
author = "Chu, {C. W.} and Testardi, {L. R.} and Schmidt, {P. H.}",
note = "Funding Information: IN THE LAST several years, extensive effort has been made in the search for possible correlation between the normal state properties and the high temperature superconductivity of A15 compounds. The discovery of high superconducting transition temperatures ( Tc) in the sputtered A15 Nb-Ge Films \[I, 2\] (in contrast to a Tc of ~ 6 K in arc-cast bulk NbaGe samples) has accelerated such a search \[3-7\].R ecent studies on Nb-Ge films with different chemical compositions \[3\],p repared under different conditions \[3\]a nd subjected to different radiation doses \[4\],r evealed simple To-lattice-parameter and To-resistance-ratio correlations: T~ increases as the lattice parameter (ao) decreases while the resistance ratio (R/R) is observed to increase. These studies led the authors \[4, 7, 8\] to the proposition that the variation in T c could be described by a single defect parameter, and that the removal of defects would enhance the To. The anomalous behavior of bulk A15 compounds both in their normal and superconducting states has also been ascribed to defects \[9, 10\]. Significant pressure induced change in the defect concentration has been proposed \[9\]W. e have determined the pressure effect on Tc and R/R of six Nb-Ge Films with Tc varying from 7.4 to 22.2 K and a V3Si f'drn with Tc of 16.6 K. Deviations from the above Tc -ao and Tc - R/R correlations were observed. All films investigated were getter-sputtered in an argon atmosphere on single crystal sapphire substrates with fflrn thicknesses between 4000 and 6000 tzm. The sample size was {"}{"} 1/8{"} wide x ~ 3/8{"} long. The details of sample preparation and analysis have been published * Research supported in part by National Science Foundation Grant No. DMR 73-02660 and by the Copyright: Copyright 2014 Elsevier B.V., All rights reserved.",
year = "1977",
month = sep,
doi = "10.1016/0038-1098(77)90965-6",
language = "English",
volume = "23",
pages = "841--844",
journal = "Solid State Communications",
issn = "0038-1098",
publisher = "Elsevier Limited",
number = "11",
}