Y和YF_3掺杂钛酸钡系PTCR材料的结构及性能

Structure and Property of Y and YF_3 Doped Barium Titanate

在不同烧结气氛下制备了Ｙ和ＹＦ_３掺杂钛酸钡材料，借助于ＸＲＤ、ＳＥＭ、ＸＲＦ和阻温测试分析仪，研究了烧结气氛对Ｙ和ＹＦ_３掺杂钛酸钡材料结构和性能的影响．研究结果表明，低氧分压气氛可促进Ｙ和ＹＦ_３掺杂钛酸钡材料的烧结，晶粒长大，而且这二种掺杂钛酸钡材料都是ｎ型半导体．经过氩气气氛烧结的Ｙ掺杂钛酸钡材料ＰＴＣＲ效应较弱；而对在氩气气氛中烧结的０．３ｍｏｌ％ＹＦ_３掺杂钛酸钡材料却观察到了较好的ＰＴＣＲ效应，这种效应的产生可能与Ｆ元素取代Ｏ位而导致材料的价控半导有关．

Positive Temperature Coefficient of Resistivity (PTCR) materials based on Yttrium and Yttrium Fluoride (YF_3) doped Barium titanate (BaTiO_3) ceramics were prepared in different sintering atmospheres, respectively. The effects of sintering atmospheres on the microstructure, property and mechanism of substitution of doped BaTiO_3 cerajmics were investigated by the means of XRD, SEM, XRF and R-T measuring instrument. Sintering in a low oxygen partial atmosphere can increase the densities of Y and YF_3 doped BaTiO_3 and make grain particle grow. Both Y and YF_3 doped BaTiO_3 ceramics are n-type semiconductor in which Y substitutes A-site and F substitutes O-site. Sintered in a argon atmosphere, Y doped BaTiO_3 exhibited little PTCR effect, however, an anomalous PTCR effect was observed when 0.3mol% YF_3doped BaTiO_3 ceramics was fired in Argon atmosphere. This phenomenon may be explained by a new O site substitution mechanism.