Effect of transition metal doping on the crystal structure and oxidation state of Sr2MgMo0.9TM0.1O6-δ compounds (TM = Co, Mn or Ni)
Abstract
We analyse the effects of the partial replacement of Mo by transition metals (Co, Mn or Ni) on the electronic and structural properties of Sr2MgMo0.9TM0.1O6-δ (SMMTM; TM is Co, Mn or Ni) compounds. The crystal structure and electronic state adopted by SMMTM compounds at high temperature in oxidizing and reducing atmospheres were studied by the combination of thermogravimetric analysis, X-ray diffraction at high temperature in a controlled atmosphere, X-ray photoelectron spectroscopy and electron paramagnetic resonance measurements. X-ray diffraction patterns at 800 °C showed that Sr2MgMoO6-δ and SMMTM have a face-centred cubic structure in both air and a 5% H2 atmosphere. Thermogravimetric analysis in oxidizing and reducing atmospheres at 800 °C indicated that the oxygen-vacancies concentration (δ) and its variation (Δδ) between an oxidizing atmosphere and a reducing atmosphere increase because of TM doping. X-ray photoelectron spectroscopy and electron paramagnetic resonance measurements showed that doping with TM also promotes an increase of the Mo5+ content in these double perovskites.
- Publication:
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Journal of Physics and Chemistry of Solids
- Pub Date:
- December 2019
- DOI:
- 10.1016/j.jpcs.2019.109084
- Bibcode:
- 2019JPCS..13509084D
- Keywords:
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- Sr<SUB>2</SUB>MgMoO<SUB>6-δ</SUB>;
- Crystalline structure;
- Electronic state;
- Transition metal doping