Quantitative analysis of proximity effect in $Nb/Co_{60}Fe_{40}$, Nb/Ni, and $Nb/Cu_{40}Ni_{60}$ bilayers

Jinho Kim; Jun Hyung Kwon; K. Char; Hyeonjin Doh; Han-Yong Choi

doi:10.1103/PhysRevB.72.014518

paper

Quantitative analysis of proximity effect in $N b / C o_{60} F e_{40}$ , Nb/Ni, and $N b / C u_{40} N i_{60}$ bilayers

arXiv:cond-mat/0504543 · doi:10.1103/PhysRevB.72.014518

Abstract

We have studied the behavior of the superconducting critical temperature Tc in $N b / C o_{60} F e_{40}$ , Nb/Ni, and $N b / C u_{40} N i_{60}$ bilayers as a function of the thickness of each ferromagnetic metal layer. The Tc s of three sets of bilayers exhibit non-monotonic behavior as a function of each ferromagnetic metal thickness. Employing the quantitative analysis based on Usadel formalism of the effect of the exchange energy, we observed that the Tc behavior of $N b / C o_{60} F e_{40}$ bilayers is in good agreement with the theoretical values over the entire range of the data. On the other hand, the Tc s of Nb/Ni and $N b / C u_{40} N i_{60}$ bilayers show a higher value in the small thickness regime than the theoretical prediction obtained from the calculation, which matches the dip position and the saturation value of Tc in the large thickness limit. This discrepancy is probably due to the weakened magnetic properties of Ni and $C u_{40} N i_{60}$ when they are thin. We discuss the values of our fitting parameters and its implication on the validity of the current Usadel formalism of the effect of the exchange energy.

10 pages, 5 figures and 1 table

Quantitative analysis of proximity effect in $N b / C o_{60} F e_{40}$ , Nb/Ni, and $N b / C u_{40} N i_{60}$ bilayers

Abstract

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Quantitative analysis of proximity effect in Nb/Co60​Fe40​, Nb/Ni, and Nb/Cu40​Ni60​ bilayers

Abstract

References in corpus (2)

Cited by in corpus (13)

Quantitative analysis of proximity effect in $N b / C o_{60} F e_{40}$ , Nb/Ni, and $N b / C u_{40} N i_{60}$ bilayers