The electronic structure of the CuRh{sub 1-x}Mg{sub x}O{sub 2} thermoelectric materials: An X-ray photoelectron spectroscopy study

Journal Article · Thu Sep 15 04:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.07.005· OSTI ID:21580241

Le, T K ^[1]; Flahaut, D ^[1]; Martinez, H; Andreu, N; Gonbeau, D ^[1]; Pachoud, E; Pelloquin, D; Maignan, A ^[2]

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1. IPREM/ECP (UMR 5254), University of Pau, Helioparc, 2 av. Pierre Angot, 64053 Pau Cedex 9 (France)
2. Laboratoire CRISMAT, UMR 6508 CNRS-ENSICAEN and IRMA FR3095, 6 Boulevard Marechal Juin, Caen Cedex 4 (France)

A detailed X-ray photoelectron spectroscopy study has been performed for the CuRh{sub 1-x}Mg{sub x}O{sub 2} (x=0, 0.04 and 0.10) series for a better understanding of the role of the Mg{sup 2+} substitution on the electrical properties and the value of the Seebeck coefficient. This study is based on an analysis of different compounds such as Rh{sub 2}O{sub 3}, Sr{sub 2}RhO{sub 4} and CuCrO{sub 2} in order to characterize different oxidation states (Rh{sup 3+} and Rh{sup 4+} in octahedral oxygen environment and Cu{sup +} in a dumbbell O-Cu-O coordination). The Cu2p signal of copper in the non-doped compounds CuCrO{sub 2} and CuRhO{sub 2} reveals different electronic structures. An evolution of the Cu2p core signal with the increase of Mg{sup 2+} content in the CuRh{sub 1-x}Mg{sub x}O{sub 2} is highlighted by XPS. The differences observed, especially for the Cu2p core peaks are discussed for the non-doped compounds CuCrO{sub 2} and CuRhO{sub 2} as for the CuRh{sub 1-x}Mg{sub x}O{sub 2} series upon Mg{sup 2+} substitution. - Graphical Abstract: The role of the Mg substitution in the CuRh{sub 1-x}Mg{sub x}O{sub 2} as a function of x (x=0, 0.04 and 0.1) has been investigated by following the evolution of the Cu2p spectra obtained by X-ray photoelectron spectroscopy. The filled peaks are assigned to main peak A and A{sub sat} satellites, the hatched peaks to main peak B and B{sub sat} satellites. Highlights: > XPS investigations on CuRh{sub 1-x}Mg{sub x}O{sub 2} (x=0-0.04-0.1) delafossites. > Influence of magnesium doping on to the electrical properties and the electronic structures. > Copper cation keeps two oxidation states Cu{sup +}/Cu{sup 2+} in the CuRh{sub 1-x}Mg{sub x}O{sub 2} (x=0-0.4-0.1) with an increase of the Cu{sup 2+}/Cu ratio with the x value. > Cu layer seems to contribute to complex electrical transport in such delafossites.

• OSTI ID: 21580241
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 9 Vol. 184; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALKALINE EARTH METALS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
COPPER
COPPER IONS
DOPED MATERIALS
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ELEMENTS
IONS
MAGNESIUM
MAGNESIUM IONS
MATERIALS
METALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PEAKS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
RHODIUM COMPOUNDS
RHODIUM IONS
RHODIUM OXIDES
SPECTROSCOPY
THERMOELECTRIC MATERIALS
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY PHOTOELECTRON SPECTROSCOPY