(CoxFe100-x)-Hf-O granular films as back layers for perpendicular recording media

(CoxFe100-x)-Hf-O granular films with various B-s and permeability were pre pared as the back layers for perpendicular recording media. The effect of t he permeability and B-s of the backlayer on the write sensitivity, output v oltage and medium noise were studied. The recording performance of the medi a with the granular backlayers was compared with that of the medium with an Fe-Si-N nano-crystalline backlayer. It was found that the medium noise and the write sensitivity did not depend on the permeability of the backlayer, while the output voltage and the reproduced sensitivity depend on the perm eability and the B-s. Compared with the Fe-Si-N backlayer, the media with t he granular backlayer exhibited smaller transition noise. The noise sources for two types of the media are also discussed. (C) 2001 Elsevier Science B .V. All rights reserved.