Nanocrystalline SrMnO3 perovskite prepared by sol-gel self-combustion method for sensor applications

Oxide compound with perovskite-type structure, SrMnO3, was investigated in view of its application as capacitive and/or resistive humidity sensor. The compound presents a porous structure with prevailing open tubular pores systems and it was obtained by sol-gel self-combustion method using polyvinyl alcohol as colloidal medium, followed by heat treatment. Air relative humidity (RH) has a big influence on sensor electric capacity. The best sensitivity as capacitive humidity sensor was found at working frequency of 40 Hz over a wide range of relative humidity (0-98% RH). At this frequency, within the interval 0-98% RH the capacity increases by 1200%, and the resistance decreases by only 18%. The sensor has a good linearity of the logCvs.RHcharacteristics. The sensor exhibits very small hysteresis, and a short response time. The investigated material holds promise for humidity monitoring applications, taking into account the low cost, a wide range of relative humidity and a low-contamination impact, as well as for the realization of some electronic components, which requires good stability of resistivity in the presence of environmental humidity factors.

Automated summary

SrMnO3, with its perovskite-type structure, shows promising potential as a humidity sensor, exhibiting high sensitivity and linearity at a working frequency of 40 Hz. Its porous structure and low-cost make it ideal for humidity monitoring applications and electronic components requiring stability under environmental humidity factors.