OPTICAL AND MAGNETOOPTICAL CONSTANTS OF MNPT3

Optically thick films of MnPt3 were deposited on quartz using de magne tron sputtering. The films were covered with an SiOx protective overco at and annealed in vacuum at 850 degrees C for 1 h to form the crystal line L1(2) (Cu3Au) cubic structure. These films have a high degree of long-range order and are highly textured with the (111) axis along the film normal. Variable angle spectroscopic ellipsometry measurements w ere taken over the spectral range of 1.2-4.2 eV to determine the optic al constants of both MnPt3 and the SiO, overcoat. Spectroscopic magnet o-optic Ken rotation and ellipticity measurements at near normal incid ence over the spectral range of 1.4-3.6 eV were used to determine the off-diagonal dielectric tensor elements for MnPt3. First-principles el ectronic-structure calculations were carried out for the ordered MnPt3 structure and from these the dielectric tensor elements of MnPt3 were calculated. The experimental and theoretical values of the diagonal c omponents of the dielectric tensor components are in good agreement. T he agreement for the off-diagonal components of the dielectric tens or is only fair.