eprintid: 1471624
rev_number: 23
eprint_status: archive
userid: 608
dir: disk0/01/47/16/24
datestamp: 2015-10-09 10:57:59
lastmod: 2021-09-20 00:13:29
status_changed: 2015-10-09 10:57:59
type: article
metadata_visibility: show
creators_name: Santos-Carballal, D
creators_name: Roldan, A
creators_name: Grau-Crespo, R
creators_name: de Leeuw, NH
title: First-principles study of the inversion thermodynamics and electronic structure of FeM2X4 (thio) spinels (M = Cr, Mn, Co, Ni; X = O, S)
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
note: This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
abstract: FeM2X4 spinels, with the magnetite structure, where M is a transition metal and X is oxygen or sulfur, are candidate materials for spin filters, one of the key devices in spintronics. We present here a computational study of the inversion thermodynamics and the electronic structure of these (thio)spinels for M=Cr,Mn,Co,Ni, using calculations based on the density functional theory with on-site Hubbard corrections (DFT+U). The analysis of the configurational free energies shows that different behavior is expected for the equilibrium cation distributions in these structures: FeCr2X4 and FeMn2S4 are fully normal, FeNi2X4 and FeCo2S4 are intermediate, and FeCo2O4 and FeMn2O4 are fully inverted. We have analyzed the role played by the size of the ions and by the crystal field stabilization effects in determining the equilibrium inversion degree. We also discuss how the electronic and magnetic structure of these spinels is modified by the degree of inversion, assuming that this could be varied from the equilibrium value. We have obtained electronic densities of states for the completely normal and completely inverse cation distribution of each compound. FeCr2X4,FeMn2X4,FeCo2O4, and FeNi2O4 are half-metals in the ferrimagnetic state when Fe is in tetrahedral positions. When M is filling the tetrahedral positions, the Cr-containing compounds and FeMn2O4 are half-metallic systems, while the Co and Ni spinels are insulators. The Co and Ni sulfide counterparts are metallic for any inversion degree together with the inverse FeMn2S4. Our calculations suggest that the spin filtering properties of the FeM2X4 (thio)spinels could be modified via the control of the cation distribution through variations in the synthesis conditions
date: 2015-05-07
date_type: published
official_url: http://dx.doi.org/10.1103/PhysRevB.91.195106
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1036861
doi: 10.1103/PhysRevB.91.195106
lyricists_name: De Leeuw, Nora
lyricists_id: NHDEL32
actors_name: De Leeuw, Nora
actors_name: Barczynska, Patrycja
actors_id: NHDEL32
actors_id: PBARC91
actors_role: owner
actors_role: impersonator
full_text_status: public
publication: PHYSICAL REVIEW B
volume: 91
number: 19
issn: 1098-0121
citation:        Santos-Carballal, D;    Roldan, A;    Grau-Crespo, R;    de Leeuw, NH;      (2015)    First-principles study of the inversion thermodynamics and electronic structure of FeM2X4 (thio) spinels (M = Cr, Mn, Co, Ni; X = O, S).                   PHYSICAL REVIEW B , 91  (19)      10.1103/PhysRevB.91.195106 <https://doi.org/10.1103/PhysRevB.91.195106>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1471624/1/PhysRevB.91.195106.pdf