Magneto-optical Kerr spectroscopy of a new chemically ordered alloy: Co3Pt

The sensitivity of magneto-optical spectra to alloy chemical ordering is established. This is demonstrated for a new ordered Co3Pt phase, which was synthesized in thin film form using molecular beam epitaxial growth. This compound consists of alternating planes of Co and CoPt atoms with a hexagonal ABAB... layer sequence. The chemical ordering is accompanied by a substantial electronic structure change as reflected in a new peak in magneto-optical spectra at ∼3.2 eV photon energy. © 1993 The American Physical Society.