稀土氧化物掺杂对BST陶瓷热释电性能的影响

Effects of rare-earth doping on the pyroelectric properties of BST ceramics

采用轧膜成型工艺制备了掺杂有稀土氧化物的钛酸锶钡(BST)陶瓷,研究了不同稀土(Sc,Y,La,Ce,Pr,Nd和Sm)氧化物掺杂对其微观形貌、介电性能和热释电性能的影响。结果表明,Sc掺杂大幅降低了BST陶瓷的εr,严重劣化了BST陶瓷的热释电性能,并引起了长条状晶粒在BST陶瓷中的出现;Y掺杂则显著提高了BST陶瓷的热释电性能,并最终获得了εr为7111、tanδ为0.65×10–2、热释电系数p为5.5×10–7C·cm–2·℃–1、探测率优值Fd为8.49×10–5Pa–1/2的热释电BST陶瓷材料,有望在红外探测领域得到应用。

A group of BaSrTiO3 （BST） ceramics doped with various kinds of rare earth oxide （REO） （including Sc, Y, La, Ce, Pr, Nd and Sin） were prepared using the roll forming technology. The effects of REO doping on the surface micromophology, dielectric properties and pyroelectric properties of the BST ceramic were studied. When Sr is doped, εr of the BST ceramic decreases dramatically while the pyroelectric properties degrade markedly, and bar-shaped grains are found in the BST ceramic. However, Y doping could improve the pyroelectric properties of the BST ceramic notably, with εr of 7 111, tanδ of 0.65×10^-2, pyroelectric coefficient p of 5.5×10^-7C ·cm^-2 · C^-1 and detectivity figure of merit Fd of 8.49× 10^-5Pa^-1/2, which is hopeful to be applied in the field of infrared detection.