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

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F13%3A00422581" target="_blank" >RIV/68378271:_____/13:00422581 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1103/PhysRevB.87.075452" target="_blank" >http://dx.doi.org/10.1103/PhysRevB.87.075452</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.87.075452" target="_blank" >10.1103/PhysRevB.87.075452</a>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BE - Teoretická fyzika

OECD FORD obor

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Projekt

<a href="/cs/project/GA202%2F09%2F0775" target="_blank" >GA202/09/0775: Mnohoúrovňová teorie povrchových slitin a nehomogenit na površích pevných látek</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2013

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review. B

ISSN

1098-0121

e-ISSN

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Svazek periodika

87

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

"075452-1"-"075452-7"

Kód UT WoS článku

000315482500011

EID výsledku v databázi Scopus

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