Cuprate-ferrate compositions for temperature independent resistive oxygen sensors

Abstract

In this contribution, the binary ceramic system La 2 CuO 4 -LaFeO 3 is investigated for resistive oxygen sensor applications. The temperature-independent characteristics that are observed for copper contents of 30% or higher are of particular interest. In order to correlate sensor characteristics and material composition, an initial model describing the complex two-phase system is proposed. It is based on the so-called generalized effective media theory (GEMT), a useful tool for describing bi-phase composites. The fitting procedure allows to predict the actual sensor characteristics determined by the experiments.

Why does the electrical conductivity in PEDOT:PSS decrease with PSS content? A study combining thermoelectric measurements with impedance spectroscopy

“…41 Typically, w is a parameter that has to be adjusted to the experimental data and includes the different aspect ratios and distributions of the single material phases. 42 We have applied eq 8 to model the conductivity of the PEDOT:PSS films. As we varied the PSS content, the volume faction of the low-conductive phase (1 À U) is used to fit the conductivity.…”

LaFeO3 ceramics as selective oxygen sensors at mild temperature

“…LaFeO 3 -based ceramics were also reported to have good sensing properties towards many gases such as acetone, formaldehyde ethanol, SO 2 , NO 2 , CO, CH 4 , CO 2 and O 2 [4][5][6][7][8][9][10][11][12][13].…”

“…Many nanocrystalline metal oxides, as single or mixed phases and composites, have been investigated as sensitive materials for O 2 sensors. Many of these devices operate at high temperature (650-1000 °C), like Ga 2 O 3 [15], BaSnO 3 [17] and La 2 CuO 4 -LaFeO 3 [12], which is a limiting factor for application requesting low power consumption. On the other hand, O 2 sensors operating at near ambient temperature, including CeO 2 [18], Pt-In 2 O 3 [19] and SrTiO 3 [20], suffer of long recovery times.…”

Aerosol-deposited BaFe<sub>0.7</sub>Ta<sub>0.3</sub>O<sub>3-δ</sub> for nitrogen monoxide and temperature-independent oxygen sensing

“…So far, many resistive thick film oxygen sensors have been produced by screen printing method, e.g., Mg-doped SrTiO 3 (Zhou et al, 1997), SrTi 0.65 Fe 0.35 O 3−δ (Menesklou et al, 1999), LaCu 0.3 Fe 0.7 O 3−δ , (Sahner et al, 2006a) and La 0.05 Sr 0.95 Ti 0.65 Fe 0.35 O 3−δ (LSTF) (Sahner et al, 2006b). Moos et al (2003) investigated LSTF thick films that were produced by screen printing method as temperatureindependent resistive oxygen sensor.…”