Optical and magneto-optical constants of MnPt3

Optically thick films of MnPt 3 were deposited on quartz using dc magnetron sputtering. The films were covered with an SiO x protective overcoat and annealed in vacuum at 850 °C for 1 h to form the crystalline L1 2 ͑Cu 3 Au͒ cubic structure. These films have a high degree of long-range order and are highly textured with the ͑111͒ axis along the film normal. Variable angle spectroscopic ellipsometry measurements were taken over the spectral range of 1.2–4.2 eV to determine the optical constants of both MnPt 3 and the SiO x overcoat. Spec-troscopic magneto-optic Kerr rotation and ellipticity measurements at near normal incidence over the spectral range of 1.4–3.6 eV were used to determine the off-diagonal dielectric tensor elements for MnPt 3. First-principles electronic-structure calculations were carried out for the ordered MnPt 3 structure and from these the dielectric tensor elements of MnPt 3 were calculated. The experimental and theoretical values of the diagonal components of the dielectric tensor components are in good agreement. The agreement for the off-diagonal components of the dielectric tensor is only fair. ͓S0163-1829͑97͒04205-7͔