Magnetic linear dichroism in photoemission from Fe on Cu₈₄Al₁₆(1 0 0) and Cu₃Au(1 0 0)

We have investigated the magnetic properties of monolayers of FCC Fe grown epitaxialy on Cu₈₄Al₁₆(1 0 0) and on ordered Cu₃Au(1 0 0), substrates that present lattice parameters 1% and 3.7% bigger than pure Cu. The magnetic measurements were carried out by linear magnetic dichroism in the angular distribution of photoelectrons (LMDAD), using linearly polarized synchrotron radiation. The LMDAD measurements of the Fe 3p core levels show that starting from 2.5 monolayers (ML) for Fe/Cu₈₄Al₁₆(1 0 0) and from 4 ML for Fe/Cu₃Au(1 0 0) these FCC Fe films present in-plane ferromagnetism. The 9% increase of the magnetic splitting of the Fe 3p LMDAD peak-to-peak asymmetry measured for Fe/Cu₃Au(1 0 0) suggests an increase of the Fe magnetic moment with increasing volume of the high-spin FCC Fe films.