C-axis oriented Ba-ferrite thin film with small grain for perpendicular magnetic recording

Hexagonal Ba-ferrite(BaM) thin films with amorphous AlO(a-AlO) under-layer were prepared by a facing targets sputtering system. The grain size of c-axis perpendicularly oriented BaM/a-AlO films is about 20 nm at the thickness of 20 nm for BaM layer. The perpendicular coercivity is about 3.5-4.3 kOe with BaM layer thickness in the range from 80 to 30 nm and 2.3 kOe for BaM layer thickness of 20 nm. The in-plane coercivity for BaM/a-AlO films was less than 0.1 kOe at the thickness ranging from 20 to 80 nm. (C) 2003 Elsevier B.V. All rights reserved.