Dielectric response of Fe2O3 crystals and thin films

Ruth A. Lunt; Adam J. Jackson; Aron Walsh

doi:10.1016/j.cplett.2013.09.023

Dielectric response of Fe₂O₃ crystals and thin films

Ruth A. Lunt, Adam J. Jackson, Aron Walsh

Department of Physics

Research output: Contribution to journal › Article › peer-review

55 Scopus citations

Abstract

We report the static (ε₀) and high frequency (ε_∞) dielectric constants of haematite (α -Fe ₂O₃) as calculated using density functional perturbation theory. The values for bulk iron oxide are ε₀¹¹ = 26.41; ε₀³³ = 17.84; ε_∞ ¹¹ = 7.87 and ε_∞³³ = 7.57. The effective static dielectric screening of porous thin-films is predicted in aqueous solutions, using effective medium theory, to range between 33 and 44 depending on the crystal packing density. The large spread in literature values (12-120) can only be explained through surface and micro-structuring effects. These results will be important for interpreting and modelling the materials behaviour, particularly in electrochemical and photoelectrochemical cells.

Original language	English
Pages (from-to)	67-69
Number of pages	3
Journal	Chemical Physics Letters
Volume	586
DOIs	https://doi.org/10.1016/j.cplett.2013.09.023
State	Published - 2013

Bibliographical note

Funding Information:
We acknowledge L.M. Peter for suggesting the problem, useful discussions with F. Marken and K.T. Butler. R.L. was funded by a Royal Society Summer Studentship, while A.J.J. is funded by EPSRC (Grant No. EP/G03768X/1 ). Access to the HECToR supercomputer was facilitated through membership of the HPC Materials Chemistry Consortium, which is funded by EPSRC (Grant No. EP/F067496 ).

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10.1016/j.cplett.2013.09.023

Cite this

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title = "Dielectric response of Fe2O3 crystals and thin films",

abstract = "We report the static (ε0) and high frequency (ε∞) dielectric constants of haematite (α -Fe 2O3) as calculated using density functional perturbation theory. The values for bulk iron oxide are ε011 = 26.41; ε033 = 17.84; ε∞ 11 = 7.87 and ε∞33 = 7.57. The effective static dielectric screening of porous thin-films is predicted in aqueous solutions, using effective medium theory, to range between 33 and 44 depending on the crystal packing density. The large spread in literature values (12-120) can only be explained through surface and micro-structuring effects. These results will be important for interpreting and modelling the materials behaviour, particularly in electrochemical and photoelectrochemical cells.",

author = "Lunt, {Ruth A.} and Jackson, {Adam J.} and Aron Walsh",

note = "Funding Information: We acknowledge L.M. Peter for suggesting the problem, useful discussions with F. Marken and K.T. Butler. R.L. was funded by a Royal Society Summer Studentship, while A.J.J. is funded by EPSRC (Grant No. EP/G03768X/1 ). Access to the HECToR supercomputer was facilitated through membership of the HPC Materials Chemistry Consortium, which is funded by EPSRC (Grant No. EP/F067496 ). ",

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AU - Lunt, Ruth A.

AU - Jackson, Adam J.

AU - Walsh, Aron

N1 - Funding Information: We acknowledge L.M. Peter for suggesting the problem, useful discussions with F. Marken and K.T. Butler. R.L. was funded by a Royal Society Summer Studentship, while A.J.J. is funded by EPSRC (Grant No. EP/G03768X/1 ). Access to the HECToR supercomputer was facilitated through membership of the HPC Materials Chemistry Consortium, which is funded by EPSRC (Grant No. EP/F067496 ).

PY - 2013

Y1 - 2013

N2 - We report the static (ε0) and high frequency (ε∞) dielectric constants of haematite (α -Fe 2O3) as calculated using density functional perturbation theory. The values for bulk iron oxide are ε011 = 26.41; ε033 = 17.84; ε∞ 11 = 7.87 and ε∞33 = 7.57. The effective static dielectric screening of porous thin-films is predicted in aqueous solutions, using effective medium theory, to range between 33 and 44 depending on the crystal packing density. The large spread in literature values (12-120) can only be explained through surface and micro-structuring effects. These results will be important for interpreting and modelling the materials behaviour, particularly in electrochemical and photoelectrochemical cells.

AB - We report the static (ε0) and high frequency (ε∞) dielectric constants of haematite (α -Fe 2O3) as calculated using density functional perturbation theory. The values for bulk iron oxide are ε011 = 26.41; ε033 = 17.84; ε∞ 11 = 7.87 and ε∞33 = 7.57. The effective static dielectric screening of porous thin-films is predicted in aqueous solutions, using effective medium theory, to range between 33 and 44 depending on the crystal packing density. The large spread in literature values (12-120) can only be explained through surface and micro-structuring effects. These results will be important for interpreting and modelling the materials behaviour, particularly in electrochemical and photoelectrochemical cells.

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