Magnetic Exchange Interactions and Estimation of TN in CsNiF3 from first principles

0307829 - ÚFM 2008 RIV PL eng J - Journal Article
Legut, Dominik - Rusz, Ján
Magnetic Exchange Interactions and Estimation of TN in CsNiF3 from first principles.
[Magnetické výměnné interakce a určení Neelovy teploty.]
Acta Physica Polonica A. Roč. 113, č. 1 (2008), s. 503-506. ISSN 0587-4246. E-ISSN 1898-794X.
[CSMAG'07. Košice, 09.07.2007-12.07.2007]
R&D Projects: GA ČR GA106/07/1078
Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10100521
Keywords : exchange interactions * magnetism * Heisenberg model * 1D ferromagnet * Neel temperature
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 0.321, year: 2008

The CsNiF3 has been for long time studied as a prototype of quasi-1D planar ferromagnetic system. At very low temperature the studied system is insulator and therefore the magnetic exchange interactions should de- cay very rapidly. We treated the magnetic exchange coupling within the Heisenberg model for the nearest neighbor interaction between the anti- ferromagnetically coupled Ni-chains. The in?uence of up to the second- - -nearest neighbors on the ferromagnetic exchange coupling along the Ni-chains was determined. The exchange interactions were calculated for the experimental volume by the density functional theory, within the all-electron approach using the local density approximation for the exchange and cor- relation. The Ne´el temperature was calculated by means of the mean-?eld theory and by the random-phase approximation method.

CsNiF3 je dlouho znam jako prototyp jedno-dimenzionalniho ferromagnetickeho systemu. Pri nizkych teplotach je tato latka izolatorem a tudiz vymenne interakce nejsou dalekosahle. Pomoci ab initio pristupu a Heisenbergova modelu jsme zpocitali vymenne interakce podel feromagnetickych retezcu z Ni-atomu. Sila interakce byla pocitana az do vzdalenosti dvou atomovych sousedu a rovnez mezi retezci. Z vypoctenych vymennych interakce byla urcena Neelova teplota pomoci teorie stredniho pole a tzv. nahodne fazove aproximace.
Permanent Link: http://hdl.handle.net/11104/0160479