Magnetization textures in NiPd nanostructures

Abstract

We have observed peculiar magnetization textures in Ni${}_{80}$Pd${}_{20}$ nanostrips using three different imaging techniques: magnetic force microscopy, photoemission electron microscopy under polarized x-ray absorption, and scanning electron microscopy with polarization analysis. The appearance of diamondlike domains with strong lateral charges and of weak-stripe structures reveals the presence of both a transverse and a perpendicular anisotropy in these nanostructures. The anisotropy is seen to reinforce as temperature decreases, as testified by observations performed at 150 K. A thermal stress model with relaxation is proposed to account for these observations. Elastic calculations coupled to micromagnetic simulations support qualitatively this model.