The paper is devoted to a numerical study of the dc electrical conductivity for ultra-thin metallic films. The cluster approach of Stein and Krey based on the quantum-mechanical Kubo formula is employed. The dc conductivity is obtained as a function of film roughness and thickness. The results indicate how the experimentally observed decrease and the 1 ML period of the resistivity vs. thickness curve can be related to the properties of the film surface.Numerische Berechnungen werden durchgefiihrt, um die statische elektrische Leitfahigkeit sehr dunner Metallschichten zu bestimmen. Es wird die von Stein und Krey vorgeschlagene, auf der quantenmechanischen Kubo-Formel basierende "Cluster"-Methode angewandt. Der elektrische Widerstand wird als Funktion der Oberflachenrauhigkeit und Schichtdicke erhalten. Die Resultate zeigen, wie die im Experiment beobachtete Abnahme und Periodizitat des dickenabhangigen Widerstands auf Eigenschaften der Oberflache bezogen werden konnen.
The density of electronic states and its spatial distribution in thin films, based on the original adaptation of the coherent‐potential approximation (CPA) (Wojtczak and others) is obtained by including the phonon–electron interactions in the form proposed by Chen et al. This new approach allows to derive the line shape for electronic levels in which the broadening is also connected with lattice vibrations. The detailed calculations are performed for 4s copper and nickel thin films with f.c.c. lattice and (100) crystallographic orientations of the surfaces. The lattice vibrations are taken in pseudoharmonic approximation.
We present calculations of the dynamic susceptibility for a non-uniform ferromagnetic metal system with interatomic exchange included. The results obtained are general and can be applied t o ordered alloys, thin films, and other non-uniform media.We consider a system described by the Hamiltonian H =xtij aldajd + 7 u . n . n. -1 ~. . $ . 3 .where a:' is the creation operator for a n electron of spin 0 at the lattice site i, t.. is the hopping integral, U. is the intraatomic Coulomb integral, and J.. is the interatomic exchange integral: We assume the'system t o b e ferromagnetic but not necessarily translationally invariant.We aim at calculating the dynamical magnetic susceptibility. The tran9-v e r s e susceptibility is given by the Green function where spin operators on the right side are in Heisenberg picture and thermal average of the commutator is taken.The magnetic susceptibility of such a model was calculated for uniform media in RPA in /1/ and in another approximation in /2/. Our approximation is essentially similar but not identical t o the one used in /2/.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.