Abstract
Magnetoplumbite type Sr-ferrite (SrM) thin films with high magneto crystalline anisotropy were deposited on Pt underlayers. It was found that Pt underlayer is effective to enhance crystallization and the c-axis orientation perpendicular to the film plane. In order to get high crystallization and high coercivity and large squareness ratio, high substrate temperature (> 500 °C) and large thickness of magnetic layer (> 50 nm) were required. In this study, SrM/Pt bilayers were prepared using mixture gasses of Ar and Kr as sputtering gas. Ar and Kr mixture gasses was effective to deposit SrM films with high c-axis orientation and better crystallization even though their thickness below 20 nm. SrM layer sputter-deposited using Ar and Kr mixture gas revealed high perpendicular coercivity Hc⊥ around 3 kOe. SrM layer were able to be dethickness below 20 nm, and crystallized at substrate temperature 450 °C.
