Investigation on electrical transport, CO sensing characteristics and mechanism for nanocrystalline La1-xCaxFeO3 sensors
Investigation on electrical transport, CO sensing characteristics and mechanism for nanocrystalline La1-xCaxFeO3 sensors
复制标题
纳米晶La1-xCaxFeO3传感器的电输运、CO传感特性和机理研究
DOI：
10.1016/j.snb.2013.08.029
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发表时间：
2014-01-01
影响因子：
8.4
通讯作者：
Hu, Jifan
中科院分区：
文献类型：
--
作者：
Shi, Changmin;Qin, Hongwei;Hu, Jifan
在纳米晶LaFeO 3中适当的Ca掺杂不仅降低了电阻，而且提高了传感响应。纳米晶La_（1-x）Ca_xFeO_3（x = 0-0.35）的电阻最小值出现在x = 0.3左右，Fe ~（4+）/Fe ~（3+）接近1。La_（1-x）Ca_xFeO_3（x = 0-0.35）的电导可用小极化子跃迁机制来描述。X射线光电子能谱（XPS）结果表明，在x = 0 ~ 0.35范围内，随着Ca的掺杂，吸附氧O-ads的比例单调增加。然而，存在一个最佳的Ca含量（约x = 0.2），以获得最高的响应，以200 ppm的CO之间的La 1-xCaxFeO 3基传感器（0
The appropriate doping of Ca in nanocrystalline LaFeO3 not only reduces the electrical resistance, but also enhances the sensing response. A minimum of resistance for nanocrystalline La1-xCaxFeO3 (x = 0-0.35) occurs at about x = 0.3 with a value of Fe4+/Fe3+approximate to 1. The electrical conduction of La1-xCaxFeO3 (x = 0-0.35) can be well described by the mechanism of small polaron hopping. Results of X-ray photoelectron spectroscopy (XPS) show that the proportion of adsorbed oxygen O-ads enhances monotonously with Ca doping from x = 0-0.35. However, there exists an optimal Ca content (about x = 0.2) for obtaining highest response to 200 ppm CO among La1-xCaxFeO3-based sensors (0