镍离子掺杂对铝酸镧红外辐射性能的影响

Effect of Ni^(3+) Doping on Infrared Radiation Properties of Lanthanum Aluminate

采用溶胶–凝胶法合成了Ni离子掺杂的LaAlO_3基高发射率红外辐射陶瓷粉体。研究表明:Ni离子掺杂能够显著提高LaAlO_3基陶瓷粉体的红外吸收性能,当Ni离子掺杂量为40%(摩尔分数)时,所制备的LaAl_(0.6)Ni_(0.4)O_(2.89)粉体红外吸收性能最佳;以LaAl_(0.6)Ni_(0.4)O_(2.89)为基料,采用铝溶胶为黏结剂,制备出3~5μm波段发射率高达0.93的红外辐射陶瓷涂层。Ni离子掺杂能够显著提高LaAlO_3基陶瓷材料红外辐射性能的物理机制在于:Ni离子进入LaAlO_3晶格后,在其带隙中引入了Ni^(3+)和Ni^(2+)杂质能级,形成了跃迁激活能仅需0.03eV的Ni^(3+)?Ni^(2+)小极化子吸收带;通过小极化子跃迁吸收,增强了LaAlO_3基陶瓷材料的红外辐射性能。这种新型的高发射率红外辐射陶瓷涂层在热工节能领域具有广阔的应用前景。

A Ni ion doped LaA103 ceramic with a high infrared emissivity was synthesized via a sol-gel process. The result shows that Ni ion doping can improve the performance of infrared absorption of LaA103 ceramic. LaAlo.6Ni0.402.89 powder prepared has the superior absorption properties when the Ni ion doping amount is 40% （in mole fraction）. The emissivity is 0.93 in the spectral region of 3-5 Ima when aluminum sol is used as a binder. The improvement of LaA103 ceramic infrared emissivity is due to Ni ion doping. Ni ion dopes into the LaA103 lattice, introducing Ni3＋ and Ni2＋ impurity levels in the band gap, and producing the activation energy of only 0.03 eV Ni3＋←→Ni^2＋ small polar on absorption band. The absorption by small polar on hopping can enhance the performance of infrared radiation LaA103. This novel material with a high infrared emissivity shows promising applications for energy-saving in the field of thermal processing equipment.