A STUDY OF THE MOISTURE EFFECTS ON SNO2 THICK-FILMS BY SENSITIVITY AND PERMITTIVITY MEASUREMENTS

被引:33
作者
MARTINELLI, G
CAROTTA, MC
PASSARI, L
TRACCHI, L
机构
[1] Physics Department, Ferrara University, Ferrara, 44100
关键词
MOISTURE; TIN OXIDE; GAS SENSOR; FILM; SENSITIVITY; PERMITTIVITY;
D O I
10.1016/0925-4005(94)01555-V
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
Pure and Pd-doped (0.4 wt.%) SnO2 samples were prepared by the screen-printing technique starting from SnO2 powder obtained with the procedures generally used for gas sensor materials. The samples were subjected to dry and wet (50% RH) air and then resistance and capacitance were measured at different frequencies; the operating temperatures of 450 and 350 degrees C, respectively, were selected for pure and Pd-doped samples, where they present the maximum sensitivity to methane. We found a correlation between the best fitting curves of the resistance and the capacitance with the imaginary and real parts of the impedance, respectively. A tentative explanation of the observed resistance and capacitance changes by the interference of the free charge distribution with the surface states is given.
引用
收藏
页码:53 / 55
页数:3
相关论文
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