(江西理工大学 冶金与化学工程学院,赣州 341000)
摘 要: 采用溶胶-凝胶法制备钙钛矿型LaFe1-x-yMgxNiyO3的化合物,并利用TG-DTA、XRD、SEM和XPS等对其进行分析和表征。结果表明:掺杂样品在0.2~2 μm波段的红外发射率较未掺杂的LaFeO3的红外发射率大幅度提高,其原因在于,掺杂离子取代铁离子进入LaFeO3晶格中,为保持化合物电价平衡,部分Fe3+转变为Fe4+,引入杂质能级,氧空位浓度增加,促进杂质能级吸收和氧空位吸收;掺杂引起的晶格畸变使得晶格振动吸收增强;此外,电子在Fe3+和Fe4+之间的极化跃迁,亦极大地提高掺杂铁酸镧的红外辐射性能。
关键字: 钙钛矿;铁酸镧;掺杂;吸收率;红外发射率
(College of Metallurgical and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China)
Abstract:A perovskite LaFe1-x-yMgxNiyO3 compound was prepared by the sol-gel method and characterized by TG-DTA, XRD, SEM, and XPS. The result shows that the infrared emissivity of the doped samples in the range of 0.2–2 μm is greatly improved than that of the undoped LaFeO3 sample. The increase of infrared emissivity of samples can be mainly attributed to the substitution of the doped ion with Fe3+ in the LaFeO3 lattice. In order to keep the balance of electrovalent compound, the substitution of the ion doping with Fe3+ introduces the energy level of Fe4+ impurity and generates oxygen vacancies, thus increasing the impurity and oxygen vacancy absorption. The lattice distortion caused by doping strengthens the lattice vibration absorption. Furthermore, the polaron hopping of electrons between Fe3+ and Fe4+ also significantly strengthens the absorption properties within the infrared radiative properties of doped lanthanum ferrite.
Key words: perovskite; lanthanum ferrite; doping; absorptivity; infrared emissivity