Local moments and magnetic correlations above the Curie temperature in thin films on and embedded in nonmagnetic substrates: Fe/Cu(100), Co/Cu(100), and Fe/W(100)
UNSPECIFIED. (2002) Local moments and magnetic correlations above the Curie temperature in thin films on and embedded in nonmagnetic substrates: Fe/Cu(100), Co/Cu(100), and Fe/W(100). PHYSICAL REVIEW B, 66 (9). -. ISSN 1098-0121Full text not available from this repository.
Official URL: http://dx.doi.org/10.1103/PhysRevB.66.094415
We describe a mean-field theory of magnetic fluctuations in layered metallic materials at finite temperatures. It has a first-principles electronic structure basis and uses the spin-polarized screened Korringa-Kohn-Rostoker method and the coherent-potential approximation to describe the effects of the fluctuating "local moments" upon the electronic structure. At no stage is there a fitting to an effective classical Heisenberg model. From this disordered local moment picture we find the layer dependent paramagnetic spin susceptibility of films and multilayers above the Curie temperature T-c which describes how the type of magnetic correlations varies layer by layer. We study thin films of Fe and Co (1-8 layers) on and embedded in nonmagnetic substrates, specifically bcc-Fe/W(100), fcc-Fe/Cu(100), and fcc-Co/Cu(100). In uncapped Fe/W(100) we find intralayer ferromagnetic correlations in all thicknesses of the iron film except in the layer nearest the W substrate in agreement with experiment. The interlayer couplings are also ferromagnetic and short ranged. There are also ferromagnetic intralayer and interlayer couplings throughout the Co films in fcc-Co/Cu(100). In the Fe/Cu(100) system the top two layers are coupled ferromagnetically and the rest antiferromagnetically. Cu capping has a profound effect upon the magnetic coupling in both Fe/Cu(100) and Co/Cu(100) with T-c showing an oscillating behavior as a function of the cap layer thickness. In contrast there is no dramatic effect when Fe films are embedded in W(100).
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||PHYSICAL REVIEW B|
|Publisher:||AMERICAN PHYSICAL SOC|
|Date:||1 September 2002|
|Number of Pages:||10|
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