Growth and characterization of Bi, Pr and Bi, Sc-substituted lutetium irongarnet films with planar magnetization for magneto-optic visualization

The series of epitaxial garnet films of general composition Lu3-x-yBixPryFe 5-zAlzO12 and Lu3-xBixFe5-y-zScyAlzO12 were grown on (111) oriented GGG (ga dolinium gallium garnet) substrates by the liquid phase epitaxy, Their magn etic and magneto-optical properties were studied using both experimental te chniques and modelling. All obtained films demonstrated generally a magneti c anisotropy close to the easy-plane type. The Pr-containing films exhibite d large negative uniaxial anisotropy and significant cubic anisotropy. The latter causes a distortion of magnetization curves in samples magnetized in a direction normal to the film plane, especially at low temperatures. The large negative uniaxial anisotropy of Pr-substituted iron garnets allows us to increase the saturation field up to 0.5 T at liquid nitrogen temperatur e. The Sc-doped films displayed small positive uniaxial anisotropy that did not exceed the shape anisotropy, The magnetization curves of these films d id not show any distortion due to the cubic anisotropy, The suitability of Pr- and Sc-doped garnets that meet the requirements for indicator layers fo r magneto-optic visualization at liquid nitrogen temperature is discussed.