Correlation between the interface structure and magnetic and transport properties for Co/Cu(110) and Ni8Fe2/Cu/Co/Cu(110) superlattices

The correlation between the interface structure and magnetic and transport properties for single-crystal Co/Cu(110) and Ni8Fe2/Cu/Co/Cu(110) superlattices has been investigated. The interface structure was changed by changing the argon acceleration voltage of the ion beam sputtering and by annealing the samples. The interface structure was analyzed by simulating the Co59 NMR spectra. NMR is sensitive to the atomic configuration, and as a result, various interface structures (atomic configuration) were obtained, while the other structures remain unchanged. There was a correlation between the atomic configuration and magnetic and transport properties, i.e., the giant magnetoresistance, the magnetization, and the interlayer exchange coupling between the ferromagnetic layers. Both interlayer exchange coupling and magnetization at the interface correlate with the interface structure. The interface structure is important in causing both antiferromagnetic coupling between magnetic layers and a large magnetic moment at the interface, and therefore plays an important role in producing giant magnetoresistance.