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Właściwości strukturalne, optyczne i elektryczne TiO2 modyfikowanego Fe2O3

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Karoń I. , Radecka M.

Materiały Ceramiczne

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2019

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tom T. 71, nr 1

17--24

PL

Celem pracy było określenie własności strukturalnych, elektrycznych i optycznych TiO2 modyfikowanego Fe2O3. Materiały TiO2-Fe2O3 syntezowano metodą zol-żel w zakresie (0-2)% mol. Fe2O3. Badania dyfrakcji promieniowania rentgenowskiego XRD wskazują, że niedomieszkowany TiO2 oraz materiały o zawartości do 0,25% mol. Fe2O3 krystalizują w strukturze rutylu. Przewodnictwo elektryczne mierzono w funkcji składu oraz temperatury (425-700 °C). Położenie i kształt krawędzi absorpcji podstawowej zależy od koncentracji domieszki. Własności strukturalne i elektryczne materiałów potwierdzają zakres tworzenia roztworów stałych.

EN

The aim of this work was to determine the structural, electrical and optical properties of the TiO2 modified with Fe2O3. Fe2O3-TiO2 materials were synthetized by the sol-gel method in the range 0-2 mol% Fe2O3. XRD X-ray diffraction studies indicate that undoped TiO2 and materials with a content of up to 0.25 mol% Fe2O3 crystallize in the rutile structure. Electrical conductivity was measured as a function of composition and temperature (425-700 °C). The location and shape of the primary absorption edge depends on the concentration of the admixture. Structural and electrical properties of materials confirm the range of solid solution formation.

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The effect of elastic and inelastic scattering on electronic transport in open systems

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Kulinowski K. , Wołoszyn M. , Radecka M. , Spisak B. J.

International Journal of Applied Mathematics and Computer Science

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2019

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tom Vol. 29, no. 3

427--437

EN

The purpose of this study is to apply the distribution function formalism to the problem of electronic transport in open systems, and to numerically solve the kinetic equation with a dissipation term. This term is modeled within the relaxation time approximation and contains two parts, corresponding to elastic or inelastic processes. The collision operator is approximated as a sum of the semi-classical energy dissipation term and the momentum relaxation term, which randomizes the momentum but does not change the energy. As a result, the distribution of charge carriers changes due to the dissipation processes, which has a profound impact on the electronic transport through the simulated region discussed in terms of the current–voltage characteristics and their modification caused by the scattering. Measurements of the current–voltage characteristics for titanium dioxide thin layers are also presented, and compared with the results of numerical calculations.

3

Electrochemical sensors based on TiO2–Fe2O3 coupled system

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Kusior A. , Karoń I. , Radecka M.

Metrology and Measurement Systems

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2020

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tom Vol. 27, nr 2

301--311

EN

Recently, transition metal oxides, which exhibit favorable catalytic abilities, have also been investigated as a material for the detection of hydrazine (N2H4). It has been reported that mixed metal oxides usually offer a higher electrochemical activity than binary oxides. In this work, a TiO2-Fe2O3 coupled system is presented as an enhanced material with major applications in electrochemical detectors. The electrochemical behavior of glassy carbon electrodes modified with TiO2-Fe2O3 in the absence and presence of hydrazine was evaluated via cyclic voltammetry (CV). Experimental results also suggest that the formation of the TiO2-Fe2O3 coupled system enhances electrochemical catalytic performance in N2H4 detection. The modificationTiO2+2 mol% Fe2O3 provides good analytical performance of detection (0.13 mM) and quantification limits (0.39 mM). The presented coupled system provides the premise for a suitable material for a stable and sensitive N2H4 sensor.

4

Impedance spectroscopy in H2 sensing with TiO2/SnO2 nanomaterials

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Szafraniak B. , Kusior A. , Radecka M. , Zakrzewska K.

Metrology and Measurement Systems

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2020

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tom Vol. 27, nr 3

417--425

EN

Alternating current a.c. measurements enable to understand the physical and chemical processes occurring in semiconductor materials. Impedance spectroscopy has been successfully applied to study the responses of gas sensors based on metal oxides, such as TiO2, SnO2 and TiO2/SnO2 nanocomposites. This work is devoted to dynamic measurements of hydrogen sensor behaviour over the temperature range of 300-450°C. Frequency dependence of the impedance signal gives evidence that 50 mol% TiO2/50 mol% SnO2 nanocomposites should be treated as resistive-type sensors. Temporal evolution of the response to 500 ppm H2 at 320°C indicates a very short response time and much longer recovery.