Measurement of T_c suppression in tungsten using magnetic impurities

Authors

Betty A. Young, Santa Clara UniversityFollow
T. Saab
Blas Cabrera
J. J. Cross
R. M. Clarke
R. A. Abusaidi

Document Type

Article

Publication Date

12-1999

Publisher

American Institute of Physics

Abstract

We have measured the effects of dilute magnetic-atom doping on the superconducting transition temperature of tungsten thin films. Our “T_c tuning” technique is accurate, precise, and simple. Experiments were performed using dc-magnetron-sputtered tungsten films with undoped values of T_c in the range of 70–150 mK. The magnetic-atom doping was achieved using ion implantation. Specific T_c suppressions of between 5% and 65% were targeted and observed in this study. The transition width of each undoped sample was ≈1 mK and the transition widths remained sharp after implantation with ⁵⁶Fe⁺ ions. Our data are in good agreement with predictions of a linear dependence of T_c suppression with increasing magnetic-atom concentration, in the small concentration limit. At higher concentrations, antiferromagnetic coupling between the magnetic dopant atoms becomes important and the T_c-suppression effect is diminished. We use our T_c data to calculate the Abrikosov–Gor’kov (AG) and Ruderman–Kittel–Kasuya–Yosida (RKKY) spin–flip relaxation parameters τAG and τRKKY. We conclude with a brief discussion of applications of the T_c-tuning technique, and present our plans for future studies in this area.

Comments

Copyright © 1999 American Institute of Physics Publishing. Reprinted with permission.

Recommended Citation

Young, B. A., Saab, T., Cabrera, B., Cross, J. J., Clarke, R. M., & Abusaidi, R. A. (1999). Measurement of Tc suppression in tungsten using magnetic impurities. Journal of Applied Physics, 86(12), 6975–6978. https://doi.org/10.1063/1.371781