Anisotropy-dependent macroscopic domain structure in wedged-permalloy/uniform-FeMn bilayers

Macroscopic domain structures have been realized in wedged-permalloy (Py)/u niform-FeMn bilayers during magnetization reversal. When the exchange aniso tropy is established perpendicular or parallel to the wedge direction, two macroscopic domains are observed. Separating these domains are a 180 degree s wall in the perpendicular geometry and an intermediate band containing la rge density of stripe-type microdomains in the parallel geometry. While the exchange field remains practically the same in both geometries, the coerci vity and squareness of the loop are much less in the parallel geometry. (C) 2000 American Institute of Physics. [S0021-8979(00)59208-1].