Exchange interactions and temperature dependence of magnetization in half-metallic Heusler alloys

E. Şaşıoğlu, L. M. Sandratskii, P. Bruno, and I. Galanakis
Phys. Rev. B 72, 184415 – Published 14 November 2005

Abstract

We study the exchange interactions in half-metallic Heusler alloys using first-principles calculations in conjunction with the frozen-magnon approximation. The Curie temperature is estimated within both mean-field (MF) and random-phase-approximation (RPA) approaches. For the half-Heusler alloys NiMnSb and CoMnSb, the dominant interaction is between the nearest Mn atoms. In this case, the MF and RPA estimations differ strongly. The RPA approach provides better agreement with the experiment. The exchange interactions are more complex in the case of full-Heusler alloys Co2MnSi and Co2CrAl where the dominant effects are the intersublattice interactions between the Mn(Cr) and Co atoms and between Co atoms at different sublattices. For these compounds, we find that both MF and RPA give very close values of the Curie temperature slightly underestimating experimental quantities. We study the influence of the lattice compression on the magnetic properties. The temperature dependence of the magnetization is calculated using the RPA method within both quantum mechanical and classical approaches.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
1 More
  • Received 28 July 2005

DOI:https://doi.org/10.1103/PhysRevB.72.184415

©2005 American Physical Society

Authors & Affiliations

E. Şaşıoğlu*, L. M. Sandratskii, and P. Bruno

  • Max-Planck-Institut für Mikrostrukturphysik, D-06120 Halle, Germany

I. Galanakis§

  • Institut of Microelectronics, NCSR “Demokritos”, 15310 Aghia Paraskevi, Athens, Greece

  • *Electronic address: ersoy@mpi-halle.de
  • Electronic address: lsandr@mpi-halle.de
  • Electronic address: bruno@mpi-halle.de
  • §Electronic address: i.galanakis@fz-juelich.de

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 72, Iss. 18 — 1 November 2005

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×