In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 19, No. 8 ( 1980-08-01), p. 1553-
Abstract:
The applicability of the superconductive transition point of Ta and Nb for use as a temperature reference point was examined. An unusual impurity effect was found in both metals; In a plot of the transition temperature ( T c ) vs. the inverse resistance ratio (1/Γ), a substitutional impurity had a larger reducing effect on T c than an interstitial impurity. The purest specimens we obtained, with Γ=5000 for Ta and Γ=4500 for Nb, were prepared by zone-melting and subsequent annealing just below the melting points under ultra-high vacuum. From their T c values and analyses of the impurity effect, the T c values of impurity-free Ta and Nb were determined as 4.4924 K and 9.2877 K, respectively, based on the 1976 Provisional 0.5 K to 30 K Temperature Scale, the currently-accepted temperature standard.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.19.1553
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
1980
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
