Abstract
Sputtered AuCo alloy films with Co content below 48 at% showed an fcc non-equilibrium alloy phase. The measured optical constants, n and k, of Au56Co44 film were similar to those of Co-bulk rather than Au-bulk. The off- diagonal components, ω·σ'xy and ω·σ''xy (σxy=σ'xy+iσ''xy), of the conductivity tensor were estimated from the optical constants and magneto-optical Kerr spectra of the alloy film. While the spectrum of the ω·σ''xy for the alloy film is also similar to that of Co-bulk, the peak position in the high- energy region shifts to a lower energy than in Co-bulk. The Kerr spectra of Au /Co / Au sandwiched and multilayer films were simulated by the effective reflectivity method, using the conductivity tensor for pure Co and Au together with that for AuCo alloy film. Assuming the formation of an alloy layer with a thickness of 5Å at the interface, the measured Kerr spectra of the sputtered multilayer films agreed well with the calculated ones.
