Next Article in Journal
On the Nature of Voltammetric Signals Originating from Hydrogen Electrosorption into Palladium-Noble Metal Alloys
Previous Article in Journal
Controlled Aloin Release from Crosslinked Polyacrylamide Hydrogels: Effects of Mesh Size, Electric Field Strength and a Conductive Polymer
Open AccessArticle

Ba-Doped Iron Oxide as a New Material for NO2 Detection

1
Laboratory of Electrochemistry and Physical-chemistry of Materials and Interfaces, UMR 5279, CNRS-Grenoble INP-Université de Savoie-Université Joseph Fourier, BP75, 38402 Saint Martin d'Hères, France
2
Department of Applied Science and Technology, Politecnico di Torino, INSTM Reference Laboratory for Ceramics Engineering, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
*
Author to whom correspondence should be addressed.
Materials 2013, 6(10), 4801-4816; https://doi.org/10.3390/ma6104801
Received: 23 September 2013 / Revised: 5 October 2013 / Accepted: 16 October 2013 / Published: 22 October 2013
Various compositions of barium-doped hematite between pure hematite (α-Fe2O3) and pure barium hexaferrite (BaFe12O19) were synthesized by solid state reaction. The XRD analyses confirmed the progressive evolution of the two crystalline phases. Tests as humidity sensors show that the electrical resistance of samples containing high proportions of hexaferrite phase is strongly influenced. Electrochemical impedance spectroscopy (EIS) analyses under air or argon revealed an intrinsic semiconducting behavior for hematite and samples doped with 3 and 4 wt % equivalent BaO. The samples containing higher proportions of barium exhibited an extrinsic semiconducting behavior characterized by a variation of the conductivity with the oxygen partial pressure. This study allowed us to define the percolation threshold of the barium hexaferrite crystalline phase in the hematite matrix. The value was estimated to hematite doped with 5 wt % BaO, i.e., 36 wt % of barium hexaferrite phase. EIS analyses under various NO2 partial pressures confirmed the sensitivity of these materials. The linearity of the response was particularly evident for the 5, 10 and 14 wt % samples. View Full-Text
Keywords: hematite; barium hexaferrite; NO2 detection; impedance measurements hematite; barium hexaferrite; NO2 detection; impedance measurements
Show Figures

Figure 1

MDPI and ACS Style

Lopez, C.; Baroni, C.; Tulliani, J.-M. Ba-Doped Iron Oxide as a New Material for NO2 Detection. Materials 2013, 6, 4801-4816.

Show more citation formats Show less citations formats

Article Access Map by Country/Region

1
Only visits after 24 November 2015 are recorded.
Back to TopTop