High temperature orthorhombic/tetragonal transition and oxygen content of Pr2-xNdxNiO4+δ (x= 0, 0.3, 1, 1.7 and 2)solid solutions

MONTENEGRO-HERNÁNDEZ, A.; VEGA-CASTILLO, J.; CANEIRO, A.; MOGNI, L.

JOURNAL OF SOLID STATE CHEMISTRY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2019 vol. 276 p. 210 - 216

0022-4596

Single-phase Ruddlesden popper of Pr2-xNdxNiO4+δ with x = 0, 0.3, 1, 1.7 and 2, were successfully synthesized by a sol-gel route. The thermal behavior of the prepared samples has been studied at the temperature range 25?800 °C in air using Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA)and High Temperature X-ray diffraction (HT-XRD). These results show that Pr2-xNdxNiO4+δ (PNNO)solid solutions undergo a transition from an orthorhombic phase to a tetragonal one at temperatures depending of Nd content. Samples with high content of Pr (x = 0 and 0.3)decompose to a mixture of phases after heated up to 800 °C. This happens due to the partial oxidation of Pr3+ leading to segregation of secondary phases. Thermal stability below 800 °C was observed for PNNO samples with x = 1, 1.7 and 2.