Abstract
A metastable state for the elongated Permalloy elements is found to exist within a short field range before magnetization reversal. From the micromagnetic simulation it exhibits a wavelike structure, and the corresponding magnetic pole density distribution shows a pattern with periodic spots along the boundary. We also use magnetic force microscopy imaging and magnetoresistance measurement, which measures the nucleation field and coercive field, to study the noncoherent magnetization reversal properties of Permalloy ellipse with long axis, short axis, and thicknesses of 18 μm, 1 μm, and 45 nm, respectively. The metastable state before switching is found to be repeatable. © 2006 American Institute of Physics.