(Ca,Fe)共掺铈酸镧陶瓷的制备及红外辐射性能研究

Preparation and Infrared Radiation Property of Lanthanum-cerium Oxide Ceramics by(Ca,Fe) Co-doping

以La_2O_3、CeO_2、Ca O和Fe_2O_3为起始原料,采用高温固相烧结工艺制备得到（Ca,Fe）共掺铈酸镧（La_（1.9）Ca_（0.1）Ce_（1.9）Fe_（0.1）O_7）红外辐射陶瓷材料。采用X射线衍射仪、扫描电子显微镜、能谱仪、紫外–可见–近红外（UV-Vis-NIR）分光光度计分别对样品的物相组成、显微结构、化学成份、UV-Vis-NIR反射率及UV-Vis吸收进行了表征,同时采用IR-2双波段红外发射率测量仪测试了样品3~5μm波段的红外发射率。结果表明：掺杂元素（Ca,Fe）均固溶进入铈酸镧晶格,共掺后样品的晶体结构也为萤石结构;（Ca,Fe）共掺样品内部形成杂质能级,强化了自由载流子吸收与杂质能级吸收,使样品红外短波段（0.75~5μm）性能由高反射转变为高吸收（辐射）,其中在0.75~2.5μm波段的平均红外吸收率为0.88,3~5μm波段的红外发射率为0.752,与未掺杂样品相比分别提高了1660%与60%。

（Ca,Fe） co-doped lanthanum-cerium oxide （La1.9Ca0.1Ce1.9Fe0.1O7） infrared radiation ceramics were prepared via solid state reaction by using La2O3, CeO2, CaO and Fe2O3 as starting materials. The phase, micro-structure, chemi- cal composition, UV-Vis-NIR refiectivity spectrum, and UV-Vis absorption spectrum of the samples were character- ized by X-ray diffractometer, scanning electron microscopy, energy dispersive X-ray spectroscopy, and UV-Vis-NIR spectrophotometer. The infrared emissivity of the samples in 3-5 txm waveband was also measured by an infrared emissometer. The phase and EDS analysis showed the co-doped sample also had fluorite structure, indicating that Ca and Fe irons entered the crystal lattice of lanthanum-cerium oxide. An impurity energy level was introduced into lan- thanum-cerium oxide by co-doping of Ca and Fe irons, which enhanced the free-carrier absorption and impurity en- ergy level absorption of the sample. This led to a significant increase of absorption and emission in the region of 0.75-5 μm, transforming lanthanum-cerium oxide ceramic from high reflection to high absorption （radiation） ceramic after （Ca,Fe） co-doping. The （Ca,Fe） co-doped sample exhibited an absorptivity of 0.88 in 0.75-2.5μm waveband andan infrared emissivity of 0.752 in 3-5 μm waveband, increasing by 1660% and 60%, respectively, as compared with that of pure La2Ce2O7 ceramic sample.