ABSENCE OF SIZE DEPENDENCE IN THE SPIN-GLASS RESISTIVITY OF AUFE WIRES

We report on the low-temperature resistivity rho(T) of AuFe spin-glass wires with a thickness around 20 nm and a linewidth varying between 3 00 mu m and 150 nm. The observed linewidth dependence of rho(T) is due to the contribution of the disorder-enhanced electron-electron intera ction, while the spin-glass contribution is independent of linewidth. However, a quantitative analysis of the rho(T) data reveals a substant ial suppression of both the amplitude of the spin-glass resistivity an d the interaction strength between magnetic impurities when compared t o bulk AuFe alloys. This may indicate the presence of a size effect re sulting from the finite spin-glass thickness.