GMR and Characterization of Microstructures in Ion-Beam Cosputtered CoAg Granular Films

Hai SANG, Gang NI, ShuiYuan ZHANG, YouWei DU, SaiPeng WONG, Ning KE, WingYiu CHEUNG

Summary :

A series of Co_xAg_1-x (0x100at.%) granular films were prepared using the ion-beam cosputtering technique at different substrate temperatures. Systematic investigations have been carried out on the giant magnetoresistance (GMR) effect and characterization of microstructures of these samples. The magnetoresistance ratio depends strongly on cobalt concentration, substrate temperature, and annealing treatment. The optimal value of GMR was observed in Co₂₂Ag₇₈ sample prepared at the temperature of 300 K. Microstructures of as-deposited and annealed samples were characterized by structural analyses. For Co₂₂Ag₇₈ sample, real-time in situ observation by TEM together with FMR spectra indicates that the size and shape of cobalt granules evolve primarily along the film plane during annealing. The results of FMR also provide that the cobalt granules remain single-domain particles after annealing at temperatures up to 700 K.

• Publication: IEICE TRANSACTIONS on Electronics Vol.E80-C No.9 pp.1161-1167
• Publication Date: 1997/09/25
• Type of Manuscript: Special Section PAPER (Special Issue on High Density Information Recording Technologies)

Authors

Hai SANG
Gang NI
ShuiYuan ZHANG
YouWei DU
SaiPeng WONG
Ning KE
WingYiu CHEUNG

Keyword

giant magnetoresistance,  microstructure,  granular film,  annealing treatment