Thermal stability and decomposition kinetics of NdNiO3−δ at 1 bar of O2. (September 2021)

• Record Type: Journal Article
• Authors: Bassou, A.A.; Machado, P.J.; Gomes, M.M.; Manjunath, B.; Vilarinho, R.; Silva, B.; Oliveira, J.; Almeida, B.; Almeida, A.; Fernandes, J.R.; Fernandes, L.S.; Moreira, J. Agostinho; Tavares, P.B.
• Is Part Of: Materials today communications. Volume 28(2021)
• Publication Date: 2021-09
• Subjects: A. Ceramics -- A. Oxides -- B. Phase transitions -- C. X-ray diffraction -- C. Raman spectroscopy; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2021.102663
• Languages: English
• ISSNs: 2352-4928

Abstract

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 Nd2 O3 phase below 0.6% molar), with an oxygen deficiency of δ = 0.082 ± 0.001. The decomposition of the NdNiO3−δ phase into Nd4 Ni3 O10 and NiO was found to start above 900 °C. On further heating, above 1050 °C, the Nd4 Ni3 O10 decomposes into Nd2 NiO4 and NiO phases. Structural parameters and Raman spectra are provided for the NdNiO3, Nd4 Ni3 O10 and Nd2 NiO4 compounds. Graphical Abstract: ga1 Highlights: Co-precipitation synthesis of NdNiO3−δ phase at low oxygen pressure, with a low value of δ = 0.082 ± 0.001. Definition of the thermal stability of NdNiO3−δ at 1 bar of O2 . Structures, lattice parameters and octahedral bond lengths and tilt angles of NdNiO3, Nd4 Ni3 O10 and Nd2 NiO4 . Raman spectra of NdNiO3, Nd4 Ni3 O10 and Nd2 NiO4 .