Itinerant ferromagnetism in the electronic localization limit.
We present Hall effect, Rxy(H), and magnetoresistance, Rxx(H), measurements of ultrathin films of Ni, Co, and Fe with thicknesses varying between 0.2 and 8 nm and resistances between 1 MOmega and 100 Omega. Both measurements show that films having a resistance above a critical value RC, (thickness below a critical value, dC) show no signs of ferromagnetism. Ferromagnetism appears only for films with R<RC, where RC is material dependent. We raise the possibility that the reason for the absence of spontaneous magnetism is the suppression of itinerant ferromagnetism by electronic disorder in the strong localization regime.
Kurzweil
N
N
The Department of Physics, Bar Ilan University, Ramat Gan 52900, Israel.
Kogan
E
E
Frydman
A
A