Supraleitung von Pb- und Sn-Schichten nach Implantation von Mn-Ionen
Abstract
Ion-implantation is a useful method when preparing dilute alloys, especially of elements with very low solubility like 3 d-transition-elements in most non-transition superconductors. A strong decrease in T c and an increase in the residual resistivity were observed in Pb- and Sn-films doped with Mn-ions. Nonlinearity in the T c -dependence which was found at very low concentrations (0-100 ppm) is caused by lattice defects. They cannot be avoided if implantation method is used. This was proved by irradiation with nonmagnetic ions of comparable mass (such as Cu or Zn). The linear part in the T c -depression is compared with results obtained with the quenched film technique by Barth (Pb-Mn) and Schertel (Sn-Mn). A discrepancy to these measurements is found in the case of Sn-Mn. The increase in film resistivity is due to lattice defects as well as magnetic impurities. The magnetic contribution ( p/c) m =(4.5 ± 0.2) μΩ cm/at-% agrees well with a theoretical calculation. Heavily doped Sn-films show a small Kondo-resistance-minimum at 7 K with a depth of 2.5‰ of the residual resistivity.
- Publication:
-
Zeitschrift fur Physik
- Pub Date:
- August 1971
- DOI:
- 10.1007/BF01400693
- Bibcode:
- 1971ZPhy..245..283B