Final-state effects in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>3</mml:mn><mml:mi>d</mml:mi></mml:math>photoelectron spectrum of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Fe</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>and comparison with<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Fe</mml:mi></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:math>

Abstract

Photoelectron-spin-polarization measurements with photon energies up to 11 eV on ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$ and energy distribution curves in the photon energy range $5<h\ensuremath{\nu}<90$ eV on magnetite ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$ and wustite (FeO) are interpreted in terms of the atomic theory of the single-ion-in-a-crystal-field model. The combination of the two different experiments yields the shapes and positions of the filled oxygen $2p$ bands and the $3{d}^{n\ensuremath{-}1}$ final states of Fe ions with a reliability previously not attained. The $3{d}^{n\ensuremath{-}1}$-multiplet structure of ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$ can be explained with the following set of parameters: $10Dq=1.75$ eV and the Racah parameter $B=645$ ${\mathrm{cm}}^{\ensuremath{-}1}$ for ${\mathrm{Fe}}^{3+}$ left behind in $B$ lattice sites; $10Dq=1.55$ eV for ${\mathrm{Fe}}^{4+}$ in $A$ sites. The difference in threshold for photoionization of ${\mathrm{Fe}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in $B$ sites is 1.0 eV. The oxygen $2p$ emission is found to be centered at 7.3 eV below the Fermi level with a full width of 3 eV at half-maximum. The $3d$-multiplet structure of ${\mathrm{Fe}}_{x}\mathrm{O}$ can be explained with $10Dq=1.7\ifmmode\pm\else\textpm\fi{}0.1$ eV and $B=800$ ${\mathrm{cm}}^{\ensuremath{-}1}$.

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