MAGNETIC THIN-FILMS HAVING A LATERAL NANOSTRUCTURAL PERIODICITY

Magnetic and magnetoresistive properties of thin films deposited on pe riodically structured substrates are studied. We used a thermodynamica l heat treatment to activate the step bunching phenomena on vicinal Si (111) substrates misoriented towards [11 (2) over bar]. Then, Co or Fe Ni magnetic layers have been grown, with thicknesses ranging between 2 0 and 100 Angstrom. Transmission electron microscopy experiments revea l a lateral pseudoperiodic variation of the epitaxial relationship of the metallic layers. Magnetometry measurements reveal an in-plane unia xial magnetic anisotropy with the easy axis parallel to the step direc tion. We discuss the relative contributions of magnetocrystalline and shape effects to the anisotropy. Surprisingly, the angular dependance of the anisotropic magnetoresistance reveal a single-domain behavior a nd a magnetization reversal by rotation, with an active area as large as 700 mu mX100 mu m. We discuss the influence of the magnetic layer t hickness on the magnetization reversal process. (C) 1997 American Inst itute of Physics.