GRAIN-SIZE EFFECTS ON GAS SENSITIVITY OF POROUS SNO2-BASED ELEMENTS
GRAIN-SIZE EFFECTS ON GAS SENSITIVITY OF POROUS SNO2-BASED ELEMENTS
复制标题
DOI：
10.1016/0925-4005(91)80207-z
复制
发表时间：
1991-02-01
影响因子：
8.4
通讯作者：
YAMAZOE, N
中科院分区：
文献类型：
--
作者：
XU, CN;TAMAKI, J;YAMAZOE, N
研究了晶粒尺寸对纯SnO 2、氧化物稳定SnO 2和掺杂SnO 2的多孔烧结SnO 2元件气敏性能的影响。当SnO 2微晶尺寸（D）被控制在5-32 nm的范围内时，发现随着D减小，H-2、CO和i-C4 H10的S急剧增加至与2L（几乎等于6 nm）相当或小于2L（几乎等于6 nm），其中L是空间电荷层的深度。然而，乙醇气体的S被发现也受到表面酸碱性质的影响，被碱性氧化物大大促进。结果表明，通过掺杂Al ~（3+）或Sb ~（5+）来控制L，即使在D相同的情况下，S也发生了很大的变化。因此，Al掺杂的SnO 2即使在大于20 nm的D处也随着L的增加而显示出高灵敏度，而Sb掺杂的SnO 2在整个D区域中不敏感。提出了一个晶粒尺寸效应模型，该模型中换能器功能由晶粒控制、颈缩控制或晶界控制机制控制，取决于D。
Effects of grain size on gas sensitivity (S) are investigated by using porous sintered SnO2 elements fabricated with pure SnO2, foreign oxide-stabilized SnO2, or impurity-doped SnO2. When the SnO2 crystallite size (D) is controlled to a size in the range 5-32 nm, S for H-2, CO and i-C4H10 is found to increase steeply as D decreases to be comparable with or less than 2L (almost-equal-to 6 nm) is both pure and stabilized elements, where L is the depth of the space-charge layer. However, S for ethyl alcohol gas is found to be also affected by surface acid-base properties, being greatly promoted by basic oxides. It is found that the control of L by doping impurities (Al3+ or Sb5+) into the SnO2 lattice results in great changes in S even when D is the same. Thus Al-doped SnO2 shows high sensitivity with increasing L even at D above 20 nm, while Sb-doped SnO2 is insensitive in the whole D region. A model for the grain-size effects is proposed, in which the transducer function is operated by a mechanism of grain control, neck control or grain-boundary control, depending on D.