Negative thermal expansion property of Er0.7Sr0.3NiO3 − δ

Abstract A new kind of negative thermal expansion (NTE) material of Er 0.7 Sr 0.3 NiO 3 −  δ is synthesized by solid-state method and investigated. It is found that Er 0.7 Sr 0.3 NiO 3 −  δ crystallizes in orthorhombic structure with rod-shaped grains. Ceramic Er 0.7 Sr 0.3 NiO 3 −  δ exhibits NTE coefficient of − 39.0 × 10 − 6 K − 1 from 655 to 780 K. The results of X-ray diffraction, temperature dependence of Raman spectroscopy and differential scanning calorimetry (DSC) suggest that the NTE phenomenon relates to its phase transition from orthorhombic to rhombohedral.