Preparation and Gas Sensing Characteristics of Nanoparticulate p-Type Semiconducting LnFeO3 and LnCrO3 Materials

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  • This work was financially supported by BMBF under contract No.03 C 0305 A. M.S. gratefully acknowledges generous support by the Studienstiftung des Deutschen Volkes. We thank T. J. Koplin and Dr. D. Sanders for helpful discussions. Supporting Information is available online from Wiley InterScience or from the authors.

Abstract

Nanoparticulate perovskite-type LnBO3 (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; B = Cr, Fe) oxides are prepared by polyol-mediated synthesis. X-ray diffraction is used to confirm the structure of the materials, and scanning electron microscopy is applied to image the sample morphology. The powders are used for the preparation of suspensions that are deposited as thick films on comb-type Pt electrodes on alumina substrates. Electrical characterization is performed by using high-throughput impedance spectroscopy. The materials exhibit p-type semiconductor behavior, and their sensitivity towards H2, CO, NO, NO2, and propylene in a temperature range from 200 to 500 °C is analyzed. In addition, the time-resolved response of the LnFeO3 materials is investigated. A correlation between the Ln–O binding energy and the sensing properties is observed.

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