Investigations of ion-implantable submicron bubble material

We have investigated (Y Sm Tm Gd) (Fe Ga Al) garnets and (Y Sm Tm Gd Lu) (Fe Al) garnets for use as 1.0 μm and 0.5 μm diameter ion-implantable bubble materials, respectively. The selection of garnet composition is based on bubble size, Q factor, temperature dependence of magnetization and anisotropy field, FMR linewidth, and magnetostriction coefficient. Measurements of these parameters, as well as the crystalline anisotropy field are given for different film compositions. Effects of samarium and lutetium addition to achieve 0.5 μm bubbles are discussed. Both film compositions were implanted with deuterium and oxygen and the implantation induced strain and uniaxial anisotropy field change were measured. Margins for 1 μm diameter bubble propagation patterns are given.