Magnetic properties of asymmetric antirectangular Ni80Fe20 arrays

The magnetic properties of antirectangular arrays (2x10 mum(2)) embedded into 800 Angstrom thick continuous Ni80Fe20 films with interhole spacing(s) in the range of 2-6 mum have been investigated. We observed that the presence of the rectangular holes strongly modifies the shape of the magnetic hysteresis loop compared with continuous film of the same thickness. Specifically, we observed that the coercivity increases dramatically with the reduction of interhole spacing due to magnetic domain wall pinning, in agreement with our magnetic force microscopy images. Complex magnetotransport curves were obtained, which is not readily explained using the conventional anisotropic magnetoresistance effect. We attribute our results to the contribution by magnetic domains to overall resistivity of the antirectangular structures. From field angle dependent magnetotransport measurements, we are able to deduce the pinning strength for different interhole spacing. (C) 2003 American Institute of Physics.