Details
| Original language | English |
|---|---|
| Pages (from-to) | 28267-28278 |
| Number of pages | 12 |
| Journal | Physical Chemistry Chemical Physics |
| Volume | 20 |
| Issue number | 44 |
| Early online date | 29 Oct 2018 |
| Publication status | Published - 2018 |
Abstract
Spinel ferrites ( T[M 1-xFe x] O[M xFe 2-x]O 4 with 0 ≤ x ≤ 1, where M is a bivalent metal ion and the superscripts denote tetrahedral and octahedral sites) are materials commonly used in electronics due to their outstanding magnetic properties. Thus, the effect of the degree of inversion, x, on these properties is well known. However, its effect on other properties of these materials has rarely been investigated in detail. Since ferrites gained much attention during the last decade as visible light active photocatalysts and photoelectrocatalysts, understanding the effect of the degree of inversion on the optical properties became necessary. Among photocatalytically and photoelectrocatalytically active spinel ferrites, zinc ferrite (ZnFe 2O 4, ZFO) is one of the most widely studied materials. In this work, five ZFO samples with degrees of inversion varying from 0.07 to 0.20 were prepared by a solid-state reaction employing different annealing temperatures and subsequent quenching. Raman and UV-Vis-NIR spectra were measured and analyzed together with theoretical results obtained from ab initio calculations. Changes in the UV-Vis-NIR spectra associated with electronic transitions of tetrahedrally and octahedrally coordinated Fe 3+ ions are distinguished. However, the optical band gap of the material remains unchanged as the degree of inversion varies. Based on the experimental and theoretical results, a new assignment for the Raman active internal modes and the electronic transitions of ZFO is proposed.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- General Physics and Astronomy
- Chemistry(all)
- Physical and Theoretical Chemistry
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In: Physical Chemistry Chemical Physics, Vol. 20, No. 44, 2018, p. 28267-28278.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Effect of the degree of inversion on optical properties of spinel ZnFe2O4
AU - Granone, Luis I.
AU - Ulpe, Anna C.
AU - Robben, Lars
AU - Klimke, Stephen
AU - Jahns, Moritz
AU - Renz, Franz
AU - Gesing, Thorsten M.
AU - Bredow, Thomas
AU - Dillert, Ralf
AU - Bahnemann, Detlef W.
N1 - Funding information: The authors would like to thank the Laboratory of Nano-and Quantum-Engineering (LNQE) and Dr Dirk Dorfs and MSc Rasmus Himstedt for their support concerning the UV-Vis-NIR diffuse reflectance measurements. Financial support from the Deutsche Forschungsgemeinschaft in the large facility support INST144/435-1FUGG @ University of Bremen and under the program SPP 1613 (BA 1137/22-1) and the Nieder-sächsisches Ministerium für Wissenschaft und Kultur (NTH-research group ‘‘ElektroBak’’), is gratefully acknowledged.
PY - 2018
Y1 - 2018
N2 - Spinel ferrites ( T[M 1-xFe x] O[M xFe 2-x]O 4 with 0 ≤ x ≤ 1, where M is a bivalent metal ion and the superscripts denote tetrahedral and octahedral sites) are materials commonly used in electronics due to their outstanding magnetic properties. Thus, the effect of the degree of inversion, x, on these properties is well known. However, its effect on other properties of these materials has rarely been investigated in detail. Since ferrites gained much attention during the last decade as visible light active photocatalysts and photoelectrocatalysts, understanding the effect of the degree of inversion on the optical properties became necessary. Among photocatalytically and photoelectrocatalytically active spinel ferrites, zinc ferrite (ZnFe 2O 4, ZFO) is one of the most widely studied materials. In this work, five ZFO samples with degrees of inversion varying from 0.07 to 0.20 were prepared by a solid-state reaction employing different annealing temperatures and subsequent quenching. Raman and UV-Vis-NIR spectra were measured and analyzed together with theoretical results obtained from ab initio calculations. Changes in the UV-Vis-NIR spectra associated with electronic transitions of tetrahedrally and octahedrally coordinated Fe 3+ ions are distinguished. However, the optical band gap of the material remains unchanged as the degree of inversion varies. Based on the experimental and theoretical results, a new assignment for the Raman active internal modes and the electronic transitions of ZFO is proposed.
AB - Spinel ferrites ( T[M 1-xFe x] O[M xFe 2-x]O 4 with 0 ≤ x ≤ 1, where M is a bivalent metal ion and the superscripts denote tetrahedral and octahedral sites) are materials commonly used in electronics due to their outstanding magnetic properties. Thus, the effect of the degree of inversion, x, on these properties is well known. However, its effect on other properties of these materials has rarely been investigated in detail. Since ferrites gained much attention during the last decade as visible light active photocatalysts and photoelectrocatalysts, understanding the effect of the degree of inversion on the optical properties became necessary. Among photocatalytically and photoelectrocatalytically active spinel ferrites, zinc ferrite (ZnFe 2O 4, ZFO) is one of the most widely studied materials. In this work, five ZFO samples with degrees of inversion varying from 0.07 to 0.20 were prepared by a solid-state reaction employing different annealing temperatures and subsequent quenching. Raman and UV-Vis-NIR spectra were measured and analyzed together with theoretical results obtained from ab initio calculations. Changes in the UV-Vis-NIR spectra associated with electronic transitions of tetrahedrally and octahedrally coordinated Fe 3+ ions are distinguished. However, the optical band gap of the material remains unchanged as the degree of inversion varies. Based on the experimental and theoretical results, a new assignment for the Raman active internal modes and the electronic transitions of ZFO is proposed.
UR - http://www.scopus.com/inward/record.url?scp=85056547438&partnerID=8YFLogxK
U2 - 10.1039/C8CP05061A
DO - 10.1039/C8CP05061A
M3 - Article
VL - 20
SP - 28267
EP - 28278
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
SN - 1463-9076
IS - 44
ER -