BaM/Pt multilayered films with fine grains and large perpendicular magnetic anisotropy for high density recording media

Journal Article · Fri Jun 01 04:00:00 EDT 2001 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1359468· OSTI ID:40203889

Matsushita, Nobuhiro; Feng, Jie; Funabashi, Nobuhiko; Nakagawa, Shigeki; Naoe, Masahiko

A magnetoplumbite type of Ba ferrite (BaM) thin layer was deposited on a 9 nm thick Pt underlayer, and excellent c-axis orientation was observed even for an 8 nm thick BaM layer, which corresponds to only three or four BaM unit cells. The grain size was almost in the same range of 60{endash}85 nm even when the BaM layer thickness t{sub BaM} decreased from 60 to 17 nm, and t{sub BaM} should be reduced below 10 nm to make a grain size smaller than 50 nm. However, the perpendicular coercivity H{sub c{perpendicular}} and squareness S{sub {perpendicular}} decreased drastically from 2.6 to 0.5 kOe and from 0.6 to 0.2, respectively, with the decrease of t{sub BaM} from 60 to 8 nm because of higher demagnetizing field and susceptibility to thermal fluctuation. On the other hand, the [BaM(5{endash}24nm)/Pt(9nm)]{sub 3} multilayer exhibited higher H{sub c{perpendicular}} and larger S{sub {perpendicular}} than the BaM/Pt bilayer for the same BaM layer thickness and H{sub c{perpendicular}} and S{sub {perpendicular}} of the [BaM(8nm)/Pt(9nm)]{sub 3} multilayer was 2.0 kOe and 0.6, respectively. It was clarified that the deposition of the BaM/Pt multilayer was very effective for achieving a high perpendicular magnetic anisotropy constant even for the ultrathin BaM layer. {copyright} 2001 American Institute of Physics.

• Sponsoring Organization: (US)
• OSTI ID: 40203889
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 89; ISSN 0021-8979
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
DEPOSITION
FERRITE
GRAIN SIZE
ORIENTATION
PHYSICS
THICKNESS