Dy-doped MnCuBi0.86 films for magneto-optic storage application

Magnetic and magneto-optic properties of MnCu1−XDyXBi0.86 (0⩽X⩽0.30) films prepared by vacuum deposition are reported. The rectangularity of the magnetic hysteresis loops and their relative remanence of MnCuBi0.86 films are improved remarkably by dysprosium doping. The coercive field increases considerably with increasing dysprosium concentration X. At the wavelength 6328 Å, the Faraday rotation at room temperature decreases with increasing dysprosium concentration from 2.7×105 deg/cm for X=0 to 1.5×105 deg/cm for X=0.30. The Faraday rotation increases gradually with decreasing wavelength. The maximum Faraday rotation appears at about 5100 Å wavelength. The magneto-optic figure of merit for transmission-type memory use decreases from about 1.3 deg for X=0 to 0.85 deg for X=0.30 at a wavelength of 6328 Å. These figures of merit are one-third to one-half of those of MnBi, but they are still greater than those of the other magneto-optic materials. The MnCu1−XDyXBi0.86(0⩽X⩽0.30) films, with excellent magnetic hysteresis characteristics, have been shown to be suitable for magneto-optic storage media.