Experimental investigation of the spin reorientation ofCo∕Aubased magnetic nanodot arrays

Abstract

͑Co/ Au͒ and ͑Au/ Co/ Au͒ nanomagnet arrays grown on nanostructured self-organized SiGe templates have been characterized by means of x-ray photoemission electron microscopy, x-ray magnetic circular dichroism, and by extended x-ray absorption spectroscopy using synchrotron radiation. In-plane magnetization is observed at room temperature for practically all Co thicknesses, a stable macroscopic perpendicular magnetic order only at low temperature. The spin reorientation transition in these dot arrays takes place for smaller Co thicknesses over a broader thickness range than in two-dimensional systems. This finding appears to be related with structural relaxation modifications, occurring within the local Co atom environment, which are not necessarily connected with the orbital moment variations. These variations appear in the form of a systematic increase, correlated with the existence of out-of-plane magnetization.

Amorphous nonstoichiometric oxides with tunable room-temperature ferromagnetism and electrical transport

“…3b shows the further analysis of the detailed Co chemical states through comparisons of Co-L 3 results of S1 film with references and calculations. The XAS features observed in our samples, although broadened in S1, are clearly different from all references, including the Co metal reference that is completely featureless [29], and CoO or Co 3 O 4 with different peak positions or intensities. We therefore performed multiplet calculations of a typical octahedral coordination of CoO (Co 2+ B), a specific Co 2+ states in distorted octahedral coordination (Co 2+ A) (see methods for theoretical Co-L XAS simulation) as well as Co 3+ .…”

“…1) due to both the increase of electron states close to Fermi level and Coulomb screening effect. However, the general lineshape, e.g., the shoulders at 776 and 778.5 eV and double peaks around 777.5 eV, sustains in all samples, which indicate the Co element in our thin films share a common chemical state, which is verified to be Co 2+ rather than the featureless Co metal spectrum [29], as discussed in the follow. Fig.…”

Stripe domains and spin reorientation transition in Fe78B13Si9 thin films produced by rf sputtering

“…7,10,11 This configuration has been predicted to be characterized by a lower energy state than that of a single domain one. 13,14 In particular, the study of this fundamental aspect plays a major role in magnetic thin films in view of their technological application in storage devices. Conversely, the magnetization orientation is determined by the effective anisotropy constant.…”

Geometrical control of the magnetization direction in high aspect-ratio PdNi ferromagnetic nanoelectrodes

“…The magneto-resistance is proportional to cos 2 (θ) [15,16], where θ is the angle between the magnetization and the current, which in our case flows along the length of the nanowire. Yet, the direction of the magnetization is determined by the direction and strength of the applied magnetic field, the intrinsic uniaxial anisotropy and the demagnetizing field of the film, which will in turn depend on the geometry (width) of the nanowire.…”