Defect chemistry-regulated design of doping CeO2 with the enhanced high-temperature low infrared emissivity property

Abstract

Currently, CeO₂ has attracted much attention due to its excellent high-temperature emissivity tunable properties, but the synergistic regulation mechanism of oxygen vacancy concentration and bandgap structure by bi-ionic doping is unclear. In this work, Sm³⁺/Ca²⁺ co-doped CeO₂-based materials were prepared by high-temperature solid-phase method (Ce_0.8Sm_2-xCa_xO_2-δ), revealing the synergistic enhancement effect of double-ion doping on lattice distortion, oxygen vacancy formation and carrier migration. It is shown that Ca²⁺/Sm³⁺ co-doping efficiently induces oxygen vacancy generation, while Sm³⁺ suppresses the lattice distortion and narrows the bandgap (2.905 eV) by reducing the difference in ionic radii, and the synergistic effect of the two doubles the high-temperature conductivity. The IR emissivity of the optimized sample is as low as 0.208 at 600 °C. This study provides a new strategy and theoretical support for the chemical design of defects in high-temperature IR stealth materials.