First-principles study of thermodynamical properties of random magnetic overlayers on fcc-Cu(001) substrate

Mašín, Martin; Bergqvist, L.; Kudrnovský, Josef; Kotrla, Miroslav; Drchal, Václav

doi:https://dx.doi.org/10.1103/PhysRevB.87.075452

Number of the records: 1

First-principles study of thermodynamical properties of random magnetic overlayers on fcc-Cu(001) substrate

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SYSNO ASEP	0422581
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	First-principles study of thermodynamical properties of random magnetic overlayers on fcc-Cu(001) substrate
Author(s)	Mašín, Martin (FZU-D) Bergqvist, L. (SE) Kudrnovský, Josef (FZU-D)_{RID, ORCID} Kotrla, Miroslav (FZU-D)_{RID, ORCID} Drchal, Václav (FZU-D)_{RID, ORCID}
Source Title	Physical Review. B - ISSN 1098-0121 Roč. 87, č. 7 (2013), "075452-1"-"075452-7"
Number of pages	8 s.
Language	eng - English
Country	US - United States
Keywords	Curie temperature ; random overlayer ; Heisenberg Hamiltonian ; first principles ; Monte Carlo simulations ; magnon spectra
Subject RIV	BE - Theoretical Physics
R&D Projects	GA202/09/0775 GA ČR - Czech Science Foundation (CSF)
Institutional support	FZU-D - RVO:68378271
UT WOS	000315482500011
EID SCOPUS	84874514868
DOI	10.1103/PhysRevB.87.075452
Annotation	We present a theoretical study of the thermodynamical properties of a fcc-Cu(001) substrate covered by an iron-cobalt monolayer as well as by an incomplete iron layer. The effective two-dimensional Heisenberg Hamiltonian is constructed from first principles and the properties of exchange interactions are investigated. The Curie temperatures are estimated using the Monte Carlo (MC) simulations and compared with a simplified approach using the random-phase approximation (RPA) in connection with the virtual-crystal approach (VCA) to treat randomness in exchange integrals. Calculations indicate a weak maximum of the Curie temperature as a function of composition of the iron-cobalt overlayer. While a good quantitative agreement between RPA-VCA and MC was found for the iron-cobalt monolayer, the RPA-VCA approach fails for low coverage due to the magnetic percolation effect. We also present a study of the effect of alloy disorder on the shape of magnon spectra of random overlayers.
Workplace	Institute of Physics
Contact	Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579
Year of Publishing	2014

Number of the records: 1