TY - JOUR
T1 - Dielectric response of Fe2O3 crystals and thin films
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.
UR - http://www.scopus.com/inward/record.url?scp=84885653414&partnerID=8YFLogxK
U2 - 10.1016/j.cplett.2013.09.023
DO - 10.1016/j.cplett.2013.09.023
M3 - Article
AN - SCOPUS:84885653414
SN - 0009-2614
VL - 586
SP - 67
EP - 69
JO - Chemical Physics Letters
JF - Chemical Physics Letters
ER -