MAGNETOOPTICAL AND STRUCTURAL-PROPERTIES OF NANOCRYSTALLINE MNBI-BASED FILMS

In this paper we discuss recent research on MnBi and MnBiX films where X denotes alloying elements whose purpose is to modify the properties of the parent compound in beneficial ways. While MnBi has a large Ker r response, large uniaxial anisotropy and can be grown in thin-film fo rm with its easy axis normal to the film plane, it also has large grai n sizes and a high-temperature structural instability near the Curie p oint, both of which are detrimental to magneto-optic recording applica tions. We report systematic studies of Al doping which show that it do es not enhance the Kerr response nor eliminate the high temperature st ructural instability. Al does, however, promote small grain sizes whic h are required for a low noise magneto-optical recording medium. Preli minary results are reported on sputtered samples with a number of othe r dopants, and some of these have promising properties.