• Tsuei, K.-D.
• Tanaka, Arata
• Gen, Masaki
• Nakamura, R.
• Meléndez Sans, Anna
• Fujinuma, Koto
• Yoshimura, Masato
• Tokunaga, Y.
• Nakamura, M.

Abstract

<jats:p>We report hard x-ray photoelectron spectroscopy on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msub><a:mi>SrFeO</a:mi><a:mn>3</a:mn></a:msub></a:math> which is one of the classical conducting transition-metal oxides with a noncollinear magnetic structure. The obtained spectra show a detailed charge-transfer (CT) satellite structure, the Fe <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mn>2</b:mn><b:msub><b:mi>p</b:mi><b:mrow><b:mn>3</b:mn><b:mo>/</b:mo><b:mn>2</b:mn></b:mrow></b:msub></b:mrow></b:math> main peak exhibits multiplet splitting, and the deterioration signs present in previous reports are absent here, allowing for a better determination of its intrinsic electronic structure. The results are well described by a <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:msub><c:mi>FeO</c:mi><c:mn>6</c:mn></c:msub></c:math> cluster model with a charge-transfer energy of about <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:mo>−</d:mo><d:mn>1.0</d:mn></d:mrow></d:math> eV, confirming the values obtained in the previous works. The negative CT energy indicates that the electronic configuration of the tetravalent Fe is <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:msup><e:mi>d</e:mi><e:mn>5</e:mn></e:msup><e:mi>L</e:mi></e:mrow></e:math> rather than <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:msup><f:mi>d</f:mi><f:mn>4</f:mn></f:msup></f:math> where <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"><g:mi>L</g:mi></g:math> represents an O <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"><h:mrow><h:mn>2</h:mn><h:mi>p</h:mi></h:mrow></h:math> hole. The small spectral weight observed at the Fermi level indicates the correlated metallic state with localized Fe <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"><i:mrow><i:mn>3</i:mn><i:mi>d</i:mi></i:mrow></i:math> electrons and mobile O <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"><j:mrow><j:mn>2</j:mn><j:mi>p</j:mi></j:mrow></j:math> holes which are governed by a large <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"><k:mrow><k:mi>d</k:mi><k:mtext>−</k:mtext><k:mi>d</k:mi></k:mrow></k:math> Coulomb interaction and negative CT energy.</jats:p><jats:sec><jats:title/><jats:supplementary-material><jats:permissions><jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement><jats:copyright-year>2024</jats:copyright-year></jats:permissions></jats:supplementary-material></jats:sec>

Topics

• impedance spectroscopy
• cluster
• x-ray photoelectron spectroscopy
• size-exclusion chromatography