Magnetic properties and polar Kerr effect of [γ-Fe/Cu] multilayers

Magnetic properties and magneto optical polar Kerr effect of [γ-Fe/Cu] multilayers grown epitaxially by MBE method have been investigated. The occurrence of the ferromagnetism, the tetragonal distortion and the perpendicular anisotropy of γ-Fe in [γ-Fe/Cu] multilayers is discussed. The critical thickness is considered to be 2 ML Fe at interface with Cu layer. In the polar Kerr effect, the new sub-valleys of Kerr rotation and the related anomaly of Kerr ellipticity in the Kerr spectra as a function of photon energy have been observed at low temperatures. The quantum well states effect depending on the exchange splitting of the d-band has been discussed as a possible origin of the anomaly.