摘要
以La 2O 3粉、Al_(2)O_(3)粉、Cr 2O 3粉、Fe 2O 3粉为原料,按照LaAl 1-x-y Cr x Fe y O 3(x=y=0,0.1,0.2,0.25)的化学计量比配料,依次经球磨、烘干、在1200℃预烧、再球磨、成型、1600℃保温2 h烧结后,制备了Cr 3+-Fe 3+共掺杂铝酸镧材料,然后利用XRD、XPS、IR等手段进行分析表征。结果表明:掺杂后产物均为钙钛矿结构化合物。Cr 3+-Fe 3+共掺杂试样在近红外波段的辐射性较未掺杂的LaAlO 3大幅提高,试样LaAl 0.5 Cr 0.25 Fe 0.25 O 3在0.76~2.5μm波段的红外发射率从0.236提高到0.83。红外发射率提高的机制在于:Cr 3+-Fe 3+共掺杂后形成了跃迁激活能仅为0.1 eV的Fe 3+Fe 4+小极化子,并且带隙中引入了对应于Cr 5+和Cr 6+的杂质能级,增强了杂质吸收和自由载流子吸收,从而提高了材料在近红外的发射率。
Cr 3+-Fe 3+co-doped lanthanum aluminate was prepared using La 2O 3 powder,Al_(2)O_(3) powder,Cr 2O 3 powder,and Fe 2O 3 powder as raw materials.The ingredients were blended stoichiometrically according to LaAl 1-x-y Cr x Fe y O 3(x=y=0,0.1,0.2,0.25),ball milled,dried,prefired at 1200℃,ball milled again,molded and sintered at 1600℃for 2 h.The doped LaAlO 3 was characterized by XRD,XPS and IR.The results show that all the doped products are perovskite structural compounds.The near-infrared radiation performance of the Cr 3+-Fe 3+co-doped samples is greatly improved compared with the undoped ones.The infrared emissivity of the sample LaAl 0.5 Cr 0.25 Fe 0.25 O 3 in the 0.76-2.5μm waveband increases from 0.236 to 0.83.The increasing mechanism of the infrared emissivity is considered as follows.After co-doping,Cr 3+-Fe 3+forms Fe 3+Fe 4+small polaron with a transition activation energy of only 0.1 eV,introducing the impurity energy levels corresponding to Cr 5+and Cr 6+.Thus the impurity absorption and free carriers absorption are enhanced,improving the emissivity in the near-infrared waveband of the material.
作者
王曲
张一帆
王刚
张伟
Wang Qu;Zhang Yifan;Wang Gang;Zhang Wei(State Key Laboratory of Advanced Refractories,Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.,Luoyang 471039,Henan,China)
出处
《耐火材料》
CAS
北大核心
2021年第2期98-101,共4页
Refractories
基金
NSFC-河南联合基金资助项目(U1904217)。
关键词
铝酸镧
红外发射率
B位掺杂
陶瓷材料
lanthanum aluminate
infrared emissivity
B site doping
ceramic material
作者简介
王曲,男,1994年生,硕士研究生。E-mail:lirrwq@163.com;通信作者:王刚,男,1972年生,博士,教授级高级工程师。E-mail:wangg@lirrc.com。
