GIANT MAGNETORESISTANCE BEHAVIOR OF GRANULAR FE AND CO-IMPLANTED AG THIN-FILMS

The magnetoresistive behavior of granular thin films prepared by Fe an d Co implantation in Ag thin films is reported. Ag thin films (similar to 2000 Angstrom) were deposited by evaporation or laser ablation ont o Si and SiO2 substrates and implanted with Fe or Co at fluence up to 10(17) at.%/cm(2). The magnetoresistive response obtained after implan tation was found to increase with the implanted fluence. An increase o f the magnetoresistive response by a factor of 3-4 can be achieved aft er annealing the films in a conventional furnace at 620 K under vacuum . The best value of magnetoresistance obtained so far is 9% at 10 K an d 1.5% at room temperature for a film implanted with Co at a fluence o f 8X10(16) at. %/cm(2) and annealed at 620 K. (C) 1998 American Vacuum Society.