First-principles study of spin-dependent thermoelectric properties of half-metallic Heusler thin films between platinum leads

Denis Comtesse, Benjamin Geisler, Peter Entel, Peter Kratzer, L. Szunyogh

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

The electronic and magnetic bulk properties of half-metallic Heusler alloys such as Co2FeSi, Co2FeAl, Co2MnSi, and Co2MnAl are investigated by means of ab initio calculations in combination with Monte Carlo simulations. The electronic structure is analyzed using the plane-wave code quantum espresso and the magnetic exchange interactions are determined using the Korringa-Kohn-Rostoker (KKR) method. From the magnetic exchange interactions, the Curie temperature is obtained via Monte Carlo simulations. In addition, electronic transport properties of trilayer systems consisting of two semi-infinite platinum leads and a Heusler layer in-between are obtained from the fully relativistic screened KKR method by employing the Kubo-Greenwood formalism. The focus is on thermoelectric properties, namely, the Seebeck effect and its spin dependence. It turns out that already thin Heusler layers provide highly spin-polarized currents. This is attributed to the recovery of half-metallicity with increasing layer thickness. The absence of electronic states of spin-down electrons around the Fermi level suppresses the contribution of this spin channel to the total conductance, which strongly influences the thermoelectric properties and results in a spin polarization of thermoelectric currents.

Original languageEnglish
Article number094410
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume89
Issue number9
DOIs
Publication statusPublished - Mar 11 2014

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Metallic films
Exchange interactions
Platinum
platinum
Seebeck effect
Thin films
Spin polarization
Electronic states
Curie temperature
thin films
Fermi level
Transport properties
Electronic structure
Recovery
electronics
Electrons
metallicity
plane waves
simulation
transport properties

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

First-principles study of spin-dependent thermoelectric properties of half-metallic Heusler thin films between platinum leads. / Comtesse, Denis; Geisler, Benjamin; Entel, Peter; Kratzer, Peter; Szunyogh, L.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 89, No. 9, 094410, 11.03.2014.

Research output: Contribution to journalArticle

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