Humidity sensing mechanism of mesoporous MgO/KCl–SiO2 composites analyzed by complex impedance spectra and bode diagrams

Humidity‐Sensing Properties of Ag0 Nanoparticles Supported on WO3‐SiO2 with Super Rapid Response and Excellent Stability

“…They recorded changes of impedance of four orders of magnitude along with 6 s response and 26 s recovery time. [17] WO 3 is a wide-band-gap, n-type-semiconductor metal oxide, and its sensing properties have been widely explored in both single and binary systems with other transitionmetal oxides. [18][19][20] The sensing properties of WO 3 are determined by the ability of tungsten ions to change their valance state upon oxidation/reduction processes.…”

Highly sensitive humidity sensors based on LiCl–Pebax 2533 composite nanofibers via electrospinning

“…When the relative humidity was low (22% RH), few water molecules were adsorbed on the surface of sensing material, and proton migrates only by hopping from site to site across the sample surface [37], so the resistance of the sensor under this relative humidity mainly comes from the intrinsic high resistance of Pebax 2533, and its impedance is mainly determined by the capacitance of sensing film. The corresponding complex impedance plot looks like a straight line and the equivalent circuit can be modeled by a constant phase element (CPE) [12] as shown in inset of Fig. 8a, the film capacitance calculated from the constant phase element was 1.6 × 10 −11 F. When RH increased to the middle region (43% and 54% RH), more water molecules are adsorbed and serial water layer is formed.…”

“…Therefore, humidity sensors have attracted tremendous attention for the purpose of detecting the humidity. In order to optimize important properties like drift, accuracy, hysteresis or temperature influences of humidity sensors, recently new materials including metal oxide [9,10], ceramic [10,11] and polymers [12][13][14] have been designed as humidity sensors. Most commercially used humidity sensors with porous ceramics or metal oxides obviously are not suitable due to a large thickness or a complex integration process [9][10][11].…”

Effect of temperature on the electrical properties of nanocrystalline CaTi1−x Fe x O3−Δ perovskite

“…Compared to samples S1 and S2, the equivalence RC parallel circuit for samples S3 and S4 exists ( Table 3) with addition of finite-length Warburg impedance (Z w ), where the sample impedance increases linearly with the decrease in frequency. It causes by diffusion process of space ions present mostly at electrode interface [57,58]. The inset indicates that the S4 has lower resistance value when compared with the other three samples (S1, S2 and S4), which shows that the resistance values of temperature dependent electroceramics decreased abundantly with sharp increase in temperature [56].…”

“…This is evident from warburg impedance introduced in both samples S3 and S4. Therefore, the observed phase angles from bode plots for samples S2, S3 and S4 are 26°, 72°and 69°, respectively [57,58].…”