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Atomic and magnetic order in the weak ferromagnet CoVSb: is it a half-metallic ferromagnet?
journal contribution
posted on 2006-05-11, 11:38 authored by L. Heyne, T. Igarashi, T. Kanomata, Klaus-Ulrich Neumann, B. Ouladdiaf, K.R.A. ZiebeckMagnetization and neutron powder diffractionmeasurements have been carried
out on CoVSb. Both the transport and magnetic properties are predicted by
band theory to depend upon the nature of the atomic order in the C1b lattice.
Calculations in which the cobalt atoms occupy the (4b) site predict half-metallic
behaviour and a ground statemoment of∼1μB per formula unitwith 1.19μB on
the vanadium atoms and −0.19 μB on the cobalt atoms. However, calculations
in which the Sb or V atoms occupy the (4b) site predict larger moments,
∼0.7 μB, on the cobalt atoms, and either zero or a negative moment on the
vanadium atoms. In contrast, the magnetizationmeasured in fields of up to 5.5 T
is small, amounting to a ferromagnetic moment per formula unit of 0.17 μB at
2K.Both the field dependence of the magnetization in the ordered phase below
Tc ∼ 48 K and the large effective moment obtained from the Curie–Weiss
susceptibility above Tc are consistent with weak itinerant ferromagnetism.
Confirmation of the small ground state moment and hence the absence of any
significant moment on the vanadium atoms was obtained from neutron powder
diffraction measurements, which also enabled the crystallographic structure
to be determined as C1b with the cobalt atoms occupying the (4b) sites. The
results showthat CoVSb is not a half-metallic ferromagnet as predicted by band
theory.
History
School
- Science
Department
- Physics
Pages
439920 bytesCitation
HEYNE et al, 2005. Atomic and magnetic order in the weak ferromagnet CoVSb: is it a half-metallic ferromagnet? Journal of Condensed Matter, 17(33), pp. 4991–4999Publisher
© Institute of PhysicsPublication date
2005Notes
This article has been published in the journal, Journal of Physics: Condensed Matter [© Institute of Physics]. The definitive version is available at: http://www.iop.org/EJ/journal/JPhysCM.ISSN
0953-8984Language
- en