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Title: Electronic and Optical Properties of a Semiconducting Spinel (Fe 2 CrO 4 )

Abstract

Epitaxial chromium ferrite (Fe 2CrO 4), prepared by state-of-the-art oxygen plasma assisted molecular beam epitaxy, is shown to exhibit unusual electronic transport properties driven by the crystallographic structure and composition of the material. By replacing 1/3 of the Fe cations with Cr converts the host ferrimagnet from a metal into a semiconductor by virtue of its fixed valence (3+); Cr substitutes for Fe at B sites in the spinel lattice. Conversely, replacing 2/3 of the Fe cations with Cr results in an insulator. Three candidate conductive paths, all involving electron hopping between Fe 2+ and Fe 3+, are identified in Fe 2CrO 4. Moreover, Fe 2CrO 4 is shown to be photoconductive across the visible portion of the electromagnetic spectrum. As a result, this material is of potential interest for important photo-electrochemical processes such as water splitting.

Authors:
 [1];  [1];  [1];  [1];  [1];  [2];  [2];  [3];  [1]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source
  3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab.
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
1389315
Alternate Identifier(s):
OSTI ID: 1401506
Grant/Contract Number:
AC02-06CH11357; #10122
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Advanced Functional Materials
Additional Journal Information:
Journal Volume: 27; Journal Issue: 9; Journal ID: ISSN 1616-301X
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; chromium ferrite; expitaxial film; photoelectronic properties

Citation Formats

Chambers, Scott A., Droubay, Timothy C., Kaspar, Tiffany C., Nayyar, Iffat H., McBriarty, Martin E., Heald, Steve M., Keavney, David J., Bowden, Mark E., and Sushko, Peter V. Electronic and Optical Properties of a Semiconducting Spinel (Fe 2 CrO 4 ). United States: N. p., 2017. Web. doi:10.1002/adfm.201605040.
Chambers, Scott A., Droubay, Timothy C., Kaspar, Tiffany C., Nayyar, Iffat H., McBriarty, Martin E., Heald, Steve M., Keavney, David J., Bowden, Mark E., & Sushko, Peter V. Electronic and Optical Properties of a Semiconducting Spinel (Fe 2 CrO 4 ). United States. doi:10.1002/adfm.201605040.
Chambers, Scott A., Droubay, Timothy C., Kaspar, Tiffany C., Nayyar, Iffat H., McBriarty, Martin E., Heald, Steve M., Keavney, David J., Bowden, Mark E., and Sushko, Peter V. Fri . "Electronic and Optical Properties of a Semiconducting Spinel (Fe 2 CrO 4 )". United States. doi:10.1002/adfm.201605040. https://www.osti.gov/servlets/purl/1389315.
@article{osti_1389315,
title = {Electronic and Optical Properties of a Semiconducting Spinel (Fe 2 CrO 4 )},
author = {Chambers, Scott A. and Droubay, Timothy C. and Kaspar, Tiffany C. and Nayyar, Iffat H. and McBriarty, Martin E. and Heald, Steve M. and Keavney, David J. and Bowden, Mark E. and Sushko, Peter V.},
abstractNote = {Epitaxial chromium ferrite (Fe2CrO4), prepared by state-of-the-art oxygen plasma assisted molecular beam epitaxy, is shown to exhibit unusual electronic transport properties driven by the crystallographic structure and composition of the material. By replacing 1/3 of the Fe cations with Cr converts the host ferrimagnet from a metal into a semiconductor by virtue of its fixed valence (3+); Cr substitutes for Fe at B sites in the spinel lattice. Conversely, replacing 2/3 of the Fe cations with Cr results in an insulator. Three candidate conductive paths, all involving electron hopping between Fe2+ and Fe3+, are identified in Fe2CrO4. Moreover, Fe2CrO4 is shown to be photoconductive across the visible portion of the electromagnetic spectrum. As a result, this material is of potential interest for important photo-electrochemical processes such as water splitting.},
doi = {10.1002/adfm.201605040},
journal = {Advanced Functional Materials},
number = 9,
volume = 27,
place = {United States},
year = {Fri Jan 13 00:00:00 EST 2017},
month = {Fri Jan 13 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
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Cited by: 1work
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  • Epitaxial Fe2CrO4 is shown to be a ferrrimagnetic semiconductor which absorbs in the visible portion of the electromagnetic spectrum and exhibits conductivity via an unusual mechanism. Cr(III) substitutes for Fe in octahedral sites and prevents nearestneighbor B-site hopping as found in Fe3O4. Rather, ab initio modeling reveals that electron exchange between Fe(II) and Fe(III) cations at A and B sites, along with A-to- A, B-to-B site hopping over greater distances, constitute three high-resistance conduction pathways through the material.
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