Humidity-sensitive properties based on liquid state LiZnVO4-doped SnO2

Ceramic humidity sensitive samples composed of the SnO2-LiZnVO4 system were synthesized in liquid state and characterized by SEM Compared with the sample synthesized in conventional solid-state reaction the sample synthesized in liquid state has the advantages of lower impedance in the low relatively humidity (RH) range and better impedance-RH linearity The effect of different levels of liquid-state doping of LiZnVO4 on the humidity-sensitive characteristics was studied It was found that humidity-sensitive characteristics and microstructure can be improved by controlling the level of liquid-doped LiZnVO4 The best results were obtained with the 10 mol% LiZnVO4-doped sample which exhibited excellent linearity in the humidity range of 11-93% RH An impedance variation of more than four orders of magnitude better impedance-RH linearity high BET surface area a narrow hysteresis loop and rapid response were obtained SEM micrographs of the grain structures and complex Impedance analysis confirm that high performance of the sensitive layer is associated with a fine microstructure morphology which is characterized by suitable rod shaped grains forming mesopores and by well-distributed LiZnVO4 additives forming a thin glassy surface covering (C) 2010 Elsevier B V All rights reserved