Effect of lanthanum content on the thermophysical properties and near-infrared reflection properties of lanthanum-cerium oxides

A series of lanthanum-cerium oxides with different lanthanum content were synthesized by low-temperature solid-state method, and the effect of lanthanum content on the thermal conductivity and near-infrared reflectance of lanthanum-cerium oxide ceramics was systematically investigated. The results indicated that the thermal conductivity of lanthanum-cerium oxide ceramics decreased significantly with the increase of lanthanum content, which was mainly due to the non-negligible phonon scattering caused by the increased point defects in the structure. Lanthanum-cerium oxide ceramics with different lanthanum content had high near-infrared reflectivity (82%) between 1200 and 2200 nm. The lanthanum-cerium oxide ceramics prepared in this work has lower thermal conductivity and higher near-infrared reflectivity, which has broad application prospects in the field of high-temperature energy saving as thermal insulation material.