Dynamic electrophysical characterization of rubidium polytungstate, Rb4W11O35, under fast humidity impact

The electrophysical reaction of rubidium polytungstate Rb4W11O35 (RWO) on fast humidity impact has been investigated by studying the influence of wet air pulse of 1-3 s of duration on the peculiarities of dynamic current-voltage (I-V-) and charge-voltage (Q-V-) loops and transient current-time (I-t-) curves. The revealed peculiarities of hysteretic I-V- and Q-V-loops and I-t-curves for RWO subjected to humidity impact were compared with similar ones observed for water damaged hydrogen-bounded ferroelectric triglycine sulphate (TGS) crystals. The obtained data indicate at least two possible scenarios of polar reaction on the humidity impact, namely protonic/ionic space charge transfer and ferroelectric-like reversible polarization in surface RWO conglomerate disturbed by dipolar H2O adsorbate. Owing to a high surface activity the RWO can be considered as one of promising materials for creating humidity sensitive elements of environment monitoring systems. The direct humidity-to-frequency conversion was realized using LC resonance or RC-relaxation generating units.