Evidence for the Kondo effect in Zn:Fe films:: A 57Fe Mossbauer effect study

Zn films doped with Fe-57 (atomic concentration c between 0.2 and 2.0 at. %) have been prepared by the coevaporation of the two metals onto a cooled substrate (T-s=80 K). In situ electrical resistance measurements on these films show resistance minima at T-K (T-K=10 K for c=1.0 at. %) which disappear in an external magnetic field B-ex=5 T and, therefore, are interpreted as Kondo minima. Fe-57 Mossbauer effect studies on the films with c=0.6 at. % taken at T=4.3 K and for various B-ex values reveal that the effective paramagnetic Fe moments mu are mu < 0.1 mu(B) for B-ex=3 T. For larger magnetic fields the magnitude of mu is increasing with increasing B-ex [mu similar to 0.30(3)mu(B) for B-ex=7 T], as expected for a spin-compensated Kondo state.