Magnetic and microstructural properties of CoCrTa/Cr/Al thin films (abstract)
- Department of Material Science and Engineering, Korea Advanced Institute of Science and Technology, Taejon (Korea)
- Division of Metals, Korea Institute of Science and Technology, Seoul (Korea)
CoCrTa/Cr/Al and CoCrTa/Cr thin films were deposited on glass substrate at 280 C using dc magnetron sputtering. Coercivity of CoCrTa/Cr films increased by introducing an Al underlayer. In 500 A CoCrTa/Cr films, coercivity increased with Cr thickness and saturated above 700 A Cr thickness ({ital Hc}=1050 Oe). On the other hand, in 500 A CoCrTa/Cr/700 A Al films, coercivity increased sharply with Cr thickness, with a maximum at 700 A Cr thick ({ital Hc}=1380 Oe). The coercivity squareness of the CoCrTa/Cr/Al and CoCrTa/Cr films was increased with increasing Cr thickness. The coercivity squareness of CoCrTa/Cr/Al films was lower than that of CoCrTa/Cr films. To study the origin of coercivity enhancement in CoCrTa/Cr films when deposited on an Al underlayer, microstructures of the two films were investigated using TEM. We controlled grain sizes of CoCrTa films by changing thickness of Cr layer. Grain size of CoCrTa films increased with increasing Cr thickness. Coercivity of CoCrTa/Cr/Al films had a maximum at a grain size of 430 A. These results suggest that the transition from single domain to multidomain could occur at a grain size of 400 A. To understand the coercivity squareness changes by the introduction of an Al underlayer, the angular variation of coercivity was measured. The magnetization of CoCrTa/Cr films was reversed by domain wall motion. On the other hand, by the incorporation of an Al underlayer, the angular variation of coercivity deviated from the domain wall motion mode. Cross-sectional TEM studies of CoCrTa/Cr/Al films showed that Cr atoms in Cr layers diffused into an Al underlayer and Al atoms were detected in both Cr and CoCrTa layers, but magnetization of the magnetic layer was not decreased. The decrease in coercivity squareness of CoCrTa/Cr/Al films would be attributed to magnetic decoupling by segregation of Al atoms in grain boundaries of CoCrTa films. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 282093
- Report Number(s):
- CONF-951101-; ISSN 0021-8979; TRN: 9608M0104
- Journal Information:
- Journal of Applied Physics, Vol. 79, Issue 8; Conference: 40. conference on magnetism and magnetic materials, Philadelphia, PA (United States), 6-9 Nov 1995; Other Information: PBD: Apr 1996
- Country of Publication:
- United States
- Language:
- English
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