Large Anisotropy Via Oblique Sputtering of Ta Underlayers

Published

May 1, 2001

Author(s)

John E. Bonevich, Robert D. McMichael, Chang H. Lee, P J. Chen, W Wyatt Miller, William F. Egelhoff Jr.

Abstract

Anisotropy fields in excess of 120 KA/m (1500 Oe) have been produced in 3 nm to 5 nm thick polycrystalline films of Co by oblique sputtering of Ta underlayers. The unusually high anisotropy is magnetostatic in origin, and is induced by corrugations on the surface of an obliquely sputtered Ta underlayer. Cross-sectional TEM reveals 4 nm columnar grains of Ta tilted toward the Ta source and elongated perpendicular to the Ta flux in the film plane. The anisotropy field of the Co film increases with both the underlayer thickness and the angle between the Ta source and the film normal. In spin valve samples, the anisotropy is attenuated by more than an order of magnitude across a 4nm thick Cu spacer. Magnetoresistance measurements on a spin value indicate less than 2 dispersion in hard axis directions, and despite the nanometer-scale roughness of the underlayer, there is a weak broadening of the ferromagnetic resonance line.

Proceedings Title

Magnetic Materials, Structures and Processing for Information Storage, Symposium | | Magnetic Materials, Structures and Processing for Information Storage | Materials Research Society

Volume

614

Conference Dates

April 24-27, 2000

Conference Title

Materials Research Society Symposium Proceedings

Pub Type

Conferences

Keywords

anisotropy, high Tc, magnetic coupling, Superconducting, susceptibility - ac

Citation

Bonevich, J. , McMichael, R. , Lee, C. , Chen, P. , , W. and Egelhoff, W. (2001), Large Anisotropy Via Oblique Sputtering of Ta Underlayers, Magnetic Materials, Structures and Processing for Information Storage, Symposium | | Magnetic Materials, Structures and Processing for Information Storage | Materials Research Society (Accessed April 25, 2024)