Chromium segregation in CoCrTa/Cr and CoCrPt/Cr thin films for longitudinal recording media

Author

Wittig, J.E. ; Nolan, T.P. ; Ross, C.A. ; Schabes, M.E. ; Tang, K. ; Sinclair, R. ; Bentley, J.

Author_Institution

Vanderbilt Univ., Nashville, TN, USA

Volume

34

Issue

4

fYear

1998

fDate

7/1/1998 12:00:00 AM

Firstpage

1564

Lastpage

1566

Abstract

Analytical electron microscopy is employed to correlate Cr segregation in Co₃₄Cr₁₂Ta₄/Cr and Co ₇₆Cr₁₂Pt₁₂/Cr films with specific microstructural features such as grain boundary misorientation. Energy-filtered (EFTEM) chemical maps show that Cr segregation occurs independently of the Cr underlayer, and is highly alloy dependent. The CoCrTa film contained extensive grain boundary Cr enrichment whereas EFTEM images from the CoCrPt media show homogeneous Cr distribution. No statistically significant Ta or Pt segregation was observed. EFTEM elemental maps and energy dispersive spectroscopy (EDS) indicate that grain boundary Cr segregation depends on the type of boundary. Quantitative analysis of the Cr levels using nanoprobe EDS shows that the random angle grain boundaries contain more Cr (23±4 at%) than 90° boundaries (17±4 at%). EDS and EFTEM composition profiles show Cr enriched grain boundaries surrounded by regions of Cr depletion

Keywords

chromium; chromium alloys; cobalt alloys; electron probe analysis; ferromagnetic materials; grain boundary segregation; magnetic thin films; platinum alloys; sputtered coatings; tantalum alloys; transmission electron microscopy; Co₃₄Cr₁₂Ta₄-Cr; Co₇₆Cr₁₂Pt₁₂-Cr; CoCrPt-Cr; CoCrPt/Cr thin films; CoCrTa-Cr; CoCrTa/Cr thin films; analytical electron microscopy; chromium segregation; energy dispersive spectroscopy; energy-filtered chemical maps; grain boundary Cr enrichment; grain boundary misorientation; homogeneous Cr distribution; longitudinal recording media; nanoprobe EDS; random angle grain boundaries; regions of Cr depletion; Chemicals; Chromium alloys; Electrons; Grain boundaries; Magnetic separation; Material storage; Perpendicular magnetic recording; Spectroscopy; Substrates; Transistors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.706616

Filename

706616