Theory of half-metallic double perovskites. II. Effective spin Hamiltonian and disorder effects

Onur Erten, O. Nganba Meetei, Anamitra Mukherjee, Mohit Randeria, Nandini Trivedi, Patrick Woodward

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Double perovskites such as Sr2FeMoO6 are materials with half-metallic ground states and ferrimagnetic Tc's well above room temperature. This paper is the second of our comprehensive theory for half-metallic double perovskites. Here we derive an effective Hamiltonian for the Fe core spins by "integrating out" the itinerant Mo electrons and obtain an unusual double-square-root form of the spin-spin interaction. We validate the classical spin Hamiltonian by comparing its results with those of the full quantum treatment presented in a companion paper. We then use the effective Hamiltonian to compute magnetic properties as a function of temperature and disorder and discuss the effect of excess Mo, excess Fe, and antisite disorder on the magnetization and Tc. We conclude with a proposal to increase Tc without sacrificing carrier polarization.

Original languageEnglish (US)
Article number165105
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume87
Issue number16
DOIs
StatePublished - Apr 4 2013
Externally publishedYes

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Hamiltonians
perovskites
disorders
Ground state
Magnetization
Magnetic properties
Polarization
proposals
Temperature
Electrons
magnetic properties
magnetization
ground state
room temperature
polarization
electrons
interactions
temperature

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Theory of half-metallic double perovskites. II. Effective spin Hamiltonian and disorder effects. / Erten, Onur; Meetei, O. Nganba; Mukherjee, Anamitra; Randeria, Mohit; Trivedi, Nandini; Woodward, Patrick.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 87, No. 16, 165105, 04.04.2013.

Research output: Contribution to journalArticle

Erten, Onur ; Meetei, O. Nganba ; Mukherjee, Anamitra ; Randeria, Mohit ; Trivedi, Nandini ; Woodward, Patrick. / Theory of half-metallic double perovskites. II. Effective spin Hamiltonian and disorder effects. In: Physical Review B - Condensed Matter and Materials Physics. 2013 ; Vol. 87, No. 16.
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