Giant magnetoresistance of Co/Au multilayer point contacts
Abstract
We have measured the giant magnetoresistance (GMR) of granular Co/Au point contacts, fabricated by deposition of [Co(0.3 nm)/Au(4 nm)] 10 multilayers with molecular beam epitaxy. Two Co deposition rates were used to obtain two types of contacts with different Co cluster size. The measured GMR ratios are in the range 5-12%. These GMRs come from the constriction region, since the current in-plane contribution of the multilayer was shorted by a thick Au cap. GMR curves characteristic of both superparamagnetic and ferromagnetic Co clusters were observed for either contact type. Device-to-device differences in the GMR ratio and in the magnetic behaviour, and sudden jumps in the GMR indicate that only a few Co clusters in the constriction generate the GMR.
- Publication:
-
Journal of Magnetism and Magnetic Materials
- Pub Date:
- June 1999
- DOI:
- 10.1016/S0304-8853(98)00608-8
- Bibcode:
- 1999JMMM..198...27W