Effects of annealing on the magnetoresistance and structure of Fe/Cr(110) superlattices.

We have performed magnetotransport, magnetization, and structural experiments on sputtered Fe~30 Å!/Cr~12 Å! ~110! superlattices that were annealed at temperatures up to 400 °C. Interestingly, their giant magnetoresistance (Dr) is enhanced at intermediate temperatures, and strongly decreased at higher temperatures. If normalized to the antiferromagnetic coupling fraction of sample, the magnetoresistance increases over the entire annealing range. From low-angle x-ray-diffraction measurements, the enhancement of Dr arises from an interface redistribution because of either a slight interdiffusion, less correlated interfaces, or both. Further annealing causes extreme interdiffusion that is detrimental for the magnetoresistance because of a loss of antiferromagnetic coupling. @S0163-1829~96!01642-6#