uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Magnetic properties and temperature-dependent half-metallicity of Co2Mn(Ga(1-x)Z(x)) (Z = Si, Ge, Sn) from first-principles calculation
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Show others and affiliations
2013 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 25, no 15, 156003- p.Article in journal (Refereed) Published
Abstract [en]

Using the first-principles exact muffin-tin orbitals method in combination with the coherent potential approximation, we investigated the magnetic properties, exchange interactions, and temperature-dependent half-metallicity of the Co2Mn(Ga(1-x)Z(x)) (Z = Si, Ge, Sn) alloys. The total magnetic moment follows perfectly a previously proposed Slater-Pauling relation, i.e., mu(0) = N-t - 24, with N-t being the number of valence electrons. The Co-Mn and Co1-Co2 (inter-sublattice) interactions are dominated by direct exchange, whereas the Co1-Co1 (intra-sublattice) interaction is characterized by superexchange. The Mn-Mn exchange interaction in Co2MnGa is of long-ranged RKKY-type. However, the Mn-Mn exchange interactions in Co(2)MnZ are relatively localized and can be attributed to superexchange. The Co-Mn, Co1-Co2 and Co1-Co1 total exchange interactions increase with x, whereas the Mn-Mn total exchange interactions show convex behavior. The calculated Curie temperature (T-C) increases with x. The ability of Z to enhance T-C follows the sequence of Si > Ge > Sn, in agreement with the experimental findings. The temperature dependence of the spin polarization at the Fermi level [P(T)] is investigated based on the disordered local moment model. P(T) drops abruptly at temperatures much lower than T-C. At temperatures higher than 200 K, the composition with higher TC generally corresponds to larger P(T).

Place, publisher, year, edition, pages
2013. Vol. 25, no 15, 156003- p.
National Category
Natural Sciences
URN: urn:nbn:se:uu:diva-198596DOI: 10.1088/0953-8984/25/15/156003ISI: 000316622400025OAI: oai:DiVA.org:uu-198596DiVA: diva2:617526
Available from: 2013-04-23 Created: 2013-04-22 Last updated: 2013-04-23Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Johansson, BörjeVitos, Levente
By organisation
Materials Theory
In the same journal
Journal of Physics: Condensed Matter
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 206 hits
ReferencesLink to record
Permanent link

Direct link