• Yatoo, Mudasir Ahmad
• Skinner, Stephen

Abstract

<jats:p>A series of Ruddlesden-Popper phase materials – La<jats:sub>3</jats:sub>PrNi<jats:sub>3</jats:sub>O<jats:sub>10-</jats:sub><jats:sub>δ</jats:sub>,<jats:sub> </jats:sub>La<jats:sub>2</jats:sub>Pr<jats:sub>2</jats:sub>Ni<jats:sub>3</jats:sub>O<jats:sub>10-δ </jats:sub>and LaPr<jats:sub>3</jats:sub>Ni<jats:sub>3</jats:sub>O<jats:sub>10-</jats:sub><jats:sub>δ </jats:sub>– were synthesised and investigated by neutron powder diffraction to understand the oxygen defect structure. The thermal expansion coefficient was calculated for all compositions and was found to be in the range of 13.0 - 13.4 × 10<jats:sup>-6</jats:sup> ˚C<jats:sup>-1</jats:sup>, which is compatible with the commonly used electrolyte materials for solid oxide fuel cells. A weak preference for Pr occupying the M(2) site in the rocksalt layer was also observed. The majority of the oxygen vacancies were confined to the perovskite layers with a particular preference for O(1) and O(5) sites at high temperatures observed by neutron diffraction measurements. Further, a preference for a curved oxygen transport pathway around the NiO<jats:sub>6</jats:sub> octahedra was observed which agrees with the published literature for these materials.</jats:p>

Topics

• perovskite
• impedance spectroscopy
• phase
• Oxygen
• neutron diffraction
• thermal expansion
• defect
• defect structure
• laser-assisted particle removal