1. Thermal stability and decomposition kinetics of NdNiO3− δ at 1 bar of O2
- Author
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Bassou, A. A., Machado, P. J., Gomes, M. M., Manjunath, B., Vilarinho, R., Silva, Bruna Andreia Nogueira Airosa, Oliveira, José A., Almeida, B. G., Almeida, A., Fernandes, J. R., Fernandes, L. S., Moreira, J. Agostinho, Tavares, P. B., and Universidade do Minho
- Subjects
A. Oxides ,Ceramics ,Science & Technology ,Phase transitions ,Ciências Naturais::Ciências Físicas ,Raman spectroscopy ,A. Ceramics ,C. Raman spectroscopy ,Oxides ,B. Phase transitions ,C. X-ray diffraction ,X-ray diffraction - Abstract
Despite the interest in rare-earth nickelates for applications, their processing under 1 bar of oxygen pressure is still challenging. In this work, we report the co-precipitation synthesis, thermal stability and thermally driven decomposition of NdNiO3 phase, in order to determine the synthesis parameters towards a pure perovskite phase. We concluded that using a 1% molar excess of Nd during preparation and posterior annealing at around 900 °C at 1 bar of O2 yields an almost pure NdNiO3−δ phase (with a hexagonal Nd2O3 phase below 0.6% molar), with an oxygen deficiency of δ = 0.082 ± 0.001. The decomposition of the NdNiO3−δ phase into Nd4Ni3O10 and NiO was found to start above 900 °C. On further heating, above 1050 °C, the Nd4Ni3O10 decomposes into Nd2NiO4 and NiO phases. Structural parameters and Raman spectra are provided for the NdNiO3, Nd4Ni3O10 and Nd2NiO4 compounds., The authors would like to acknowledge Fundacao para a Ciencia e Tecnologia (FCT) through projects NORTE/01/0145/FEDER/028538, CERN/FIS-PAR/0005/2017, CERN/FIS-TEC/0003/2019, PTDC/FIS-MAC/29454/2017 and when appropriate co-financed by FEDER under PT2020 Partnership Agreement: CQVR: UIDB/QUI/00616/2020; IFIMUP-IN: Norte-070124-FEDER-000070; NECL: NORTE-01-0145-FEDER-022096, UID/NAN/50024/2019. P. Machado and J. Oliveira acknowledge FCT through Ph.D. Grants SFRH/BD/108509/2015 and SFRH/BD/146886/2019 respectively. A special acknowledgment is made to CEMUP for XPS measurements.
- Published
- 2021