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The fabrication and magnetization reversal mechanism of a self-aligned Ni/Ni80Fe20/Fe lateral heterostructure (LH) are presented. Using a combination of angled deposition and multiple selective etching processes, high quality LHs are successfully fabricated consisting of an array of bi-component dots made of a lens and a crescent of two different materials surrounded by antidot of a third material. Three materials, Ni, NiFe, and Fe, are combined in different orders to make the lens, crescent, and antidot. In isolated bi-component dots without the antidot matrix, the region with lower MS first undergoes a single-domain reversal followed by the vortex nucleation-annihilation reversals of the region with higher MS. In the LH, the antidot matrix interacts magnetostatically with the bi-component dots and modifies the switching fields, with the reversal process depending on which material forms the antidot. The fabrication technique and the tunable reversal process presented in this work are useful for designing functional magnetoelectronic devices. [ABSTRACT FROM AUTHOR]

Large-area arrays of magnetic Ni80Fe20 cylindrical nanoshells, nanocups, and perforated nanocups were synthesized using oblique deposition into topographical templates patterned using laser interference lithography. The geometry of the template and the tilt angle of the sample during deposition provide versatile control over the final geometry and dimension of nanostructures with thickness below 10 nm. Decreasing shell thickness led to a magnetization switching path between onion (bidomain) and reverse onion states, bypassing the vortex (flux-closed) state. The variation of magnetization reversal processes with geometry was characterized using vibrating sample magnetometry, and the results were in good agreement with micromagnetic simulations. [ABSTRACT FROM AUTHOR]

The magnetization reversal processes of rectangular and circular permalloy ring arrays are compared. Rectangular rings reverse via two different processes, one of which includes the formation of a vortex state. The corners of the rectangular rings affect domain wall pinning and reverse domain nucleation processes and alter the field values for the two major transitions between magnetic states as compared to a circular ring. The effects of film thickness are also investigated. Micromagnetic simulations are compared with the experiment results. [ABSTRACT FROM AUTHOR]