Structure and magnetic properties of electrodeposited Co films onto Si(100)

The study of magnetic multilayers consisting of electrodeposited Co layers is gaining significant importance for the application in the field of magnetic recording. However, there are been few studies on the properties of electrodeposited Co thin films. in this paper, the relation between morphology, crystallographic structure and magnetic properties of electrodeposited Co films on Si(100) and on a polycrystalline Cu substrate has been investigated. Co films of 100-nm thickness on Si and on Cu exhibit similar magnetic properties. It appears that the grain size and the interfacial roughness of the Co films do not influence significantly the magnetic properties, while the crystallographic structure plays a predominant role. We have shown that the pH of the electrolyte influences the fraction of the hcp and fee phase in the Co film and therefore tunes its magnetic properties. (C) 2000 Elsevier Science B.V. All rights reserved.status: publishe

Enhanced Kerr rotation in electrodeposited nickel films

status: publishe

Ultra-sensitive spin-valve structures grown on n-GaAs by single bath electrodeposition

Soft switching spin-valve like Co/Cu structures have been electrodeposited onto n-type (100)-GaAs. A symmetric spin-valve configuration is used which incorporates an artificially hard substructure. A magnetoresistance change of up to 6% is observed with high sensitivities ranging up to 0.67% per Oe. The magnetoresistance measurements show characteristics potentially useful for sensing applications, such as a strong angular dependence, together with a double switching step at certain angles. (C) 2000 Elsevier Science S.A. All rights reserved.status: publishe

Growth Rate Determination through Automated TEM Image Analysis: Crystallization Studies of Doped SbTe Phase-Change Thin Films

A computer-controlled procedure is outlined here that first determines the position of the amorphous-crystalline interface in an image. Subsequently, from a time series of these images, the velocity of the crystal growth front is quantified. The procedure presented here can be useful for a wide range of applications, and we apply the new approach to determine growth rates in a so-called fast-growth-type phase-change material. The growth rate (without nucleation) of this material is of interest for comparison with identical material used in phase-change random access memory cells. Crystal growth rates in the amorphous phase-change layers have been measured at various temperatures using in situ heating in a transmission electron microscope. Doped SbTe films (20 nm thick) were deposited on silicon nitride membranes, and samples with and without silicon oxide capping layer were studied. The activation energy for growth was found to be 3.0 eV. The samples without capping layer exhibit a nucleation rate that is an order of magnitude higher than the samples with a silicon oxide capping layer. This difference can be attributed to the partial oxidation of the phase-change layer in air. However, the growth rates of the samples with and without capping are quite comparable.