M. Murakami, J. Angelillo, et al.
Thin Solid Films
Previous investigators have studied the proximity effect of a number of nontransition-metal superconductors. In this investigation the proximity effect of Nb (a transition-metal superconductor) has been studied using the Nb-Cu and Nb-Ni systems. The films were sputtered sequentially without breaking vacuum. The sandwiches were maintained at temperatures below 200A°K until after Tc had been measured, to preclude chemical or metallurgical interactions. Sandwich Tc has been obtained as a function of Nb film thickness for thick overlayer films. The Nb-Cu data are in agreement with the de Gennes-Werthamer theory. The Nb-Ni data follow the form of the adjustable-parameter (βa2πkBτs) theory proposed by Werthamer. However, Ni is found to have less effect on Nb than was reported for Pb: a value of β=7 is obtained for Nb compared to β=43 for Pb. Possible explanations of the observed behavior are discussed. © 1968 The American Physical Society.
M. Murakami, J. Angelillo, et al.
Thin Solid Films
C.J. Kircher, J.W. Mayer, et al.
Applied Physics Letters
S.K. Lahiri, S. Basavaiah, et al.
Applied Physics Letters
C.J. Kircher
Solid-State Electronics