Development of columnar microstructure in magnetron sputter deposited CoPtCr/Cr magnetic thin films

Author

Kim, Myong R. ; Guruswamy, Sivaraman ; Johnson, Kenneth E.

Author_Institution

Dept. of Metall. Eng., Utah Univ., Salt Lake City, UT, USA

Volume

29

Issue

6

fYear

1993

fDate

11/1/1993 12:00:00 AM

Firstpage

3688

Lastpage

3690

Abstract

The microstructure of CoPtCr alloy thin films, sputter deposited on Cr-underlayers varying in thickness from 25 to 1300 Å, is examined. The cross-sectional as well as plane-view high resolution transmission electron microscopy (HRTEM) of these films revealed that fine Cr-underlayer grains nucleate randomly and grow on the surface of a textured NiP substrate during the early stage of sputter deposition. The heterogeneously nucleated Cr grains result in the formation of columnar grains through competitive growth. The width of columnar grains gradually increased with film thickness and saturated at a thickness of about 850 Å Cr-underlayer films. High resolution electron microscopy of these films showed the onset of physical separation between columnar grains occurred between 250 and 600 Å. The study provides insights into the evolution of thin film microstructure during sputter deposition and into the reported low noise in CoPtCr/Cr films with ultra-thin Cr underlayers

Keywords

chromium; chromium alloys; cobalt alloys; ferromagnetic properties of substances; grain boundary segregation; magnetic recording; magnetic thin films; nucleation; platinum alloys; sputter deposition; transmission electron microscope examination of materials; 25 to 1300 angstroms; CoPtCr-Cr-NiP; Cr underlayer grain nucleation; HRTEM; columnar grains; columnar microstructure; film thickness; grain boundary; high resolution electron microscopy; longitudinal magnetic recording media; magnetic thin films; magnetron sputter deposition; plane-view high resolution transmission electron microscopy; solute segregation; Chromium alloys; Electrons; Magnetic films; Magnetic noise; Magnetic separation; Microstructure; Morphology; Saturation magnetization; Sputtering; Substrates;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.281270

Filename

281270