Electrical conductivity in non-stoichiometric titanium dioxide at elevated temperatures

Balachandran, U.; Eror, N. G.

doi:10.1007/bf00547436

Cited by 119 publications

(106 citation statements)

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“…Since the specimen used in the present investigations was very pure, the latter behaviour should be considered in terms of Ti vacancies, rather than extrinsic acceptor as it was suggested by Balachandran and Eror [28].…”

Section: Discussionmentioning

confidence: 89%

“…Figure 3 represents a collection of the reported electrical conductivity data at 1273 K. As seen, there is a substantial scatter of both absolute values of data and their temperature dependence. This collection of TiO at 1273 K determined in the present work along with the data reported in the literature [6,11,19,28,29,31,32] showing the discrepancies in the absolute values of data and their…”

Section: Brief Reference Overviewmentioning

confidence: 94%

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Electrical properties of polycrystalline TiO₂ at elevated temperatures. Electrical conductivity

Nowotny

Бак

Burg

2007

Physica Status Solidi (b)

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IN MEMORIAM. This paper is dedicated to the memory of Dr. J. Bruce Wagner, Jr. (1926–2006), long time Professor of Materials Science and Engineering at the Northwestern University, Evanston, IL and Regents Professor of the Arizona State University, Tempe, AZ. Professor Wagner was prominent scientist in the area of solid‐state science, electrochemistry and high temperature chemistry. He served as Director of the Material Research Centre at the Technological Institute of Northwestern University, Director of the Centre for Solid State Science at the Arizona State University. He was also the President of the Electrochemical Society.The present work reports the electrical properties for high purity polycrystalline TiO2 using the measurements of electrical conductivity in the temperature range 1123–1323 K and in the gas phase of controlled oxygen activity (10–13 Pa < p (O2) < 105 Pa). The slope of the log σ vs. log p (O2) dependence is –1/5.4, which is considered in terms of mixed electronic and ionic compensation. The electrical conductivity data within the n –p transition were used for the determination of the conductivity components related to electrons, electron holes and ions. These data were used for the determination of the n –p transition point. The band gap determined from the conductivity components related to electronic charge carriers is equal to 2.8 eV. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Discussionmentioning

confidence: 89%

Section: Brief Reference Overviewmentioning

confidence: 94%

Electrical properties of polycrystalline TiO₂ at elevated temperatures. Electrical conductivity

Nowotny

Бак

Burg

2007

Physica Status Solidi (b)

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“…This conclusion is in broad agreement with the results of Knauth and Tuller, 48 who explained the ionic conductivity behavior of nanocrystalline anatase in terms of a mechanism involving both Frenkel and Ti reduction reactions. In contrast, rutile is usually [50][51][52][53][54][55] Defect Clusters. It is well-known that interactions between charged defects can lead to defect clustering or trapping in metal oxides.…”

Section: Resultsmentioning

confidence: 99%

Defect Chemistry, Surface Structures, and Lithium Insertion in Anatase TiO₂

2006

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Atomistic simulation techniques are used to investigate the defect properties of anatase TiO 2 and Li x TiO 2 both in the bulk and at the surfaces. Interatomic potential parameters are derived that reproduce the lattice constants of anatase, and the energies of bulk defects and surface structures are calculated. Reduction of anatase involving interstitial Ti is found to be the most favorable defect reaction in the bulk, with a lower energy than either Frenkel or Schottky reactions. The binding energies of selected defect clusters are also presented: for the Ti 3+ -Li + defect cluster, the binding energy is found to be approximately 0.5 eV, suggesting that intercalated Li ions stabilize conduction band electrons. The Li ion migration path is found to run between octahedral sites, with an activation energy of 0.45-0.65 eV for mole fractions of lithium in Li x TiO 2 of x e 0.1. The calculated surface energies are used to predict the crystal morphology, which is found to be a truncated bipyramid in which only the (101) and (001) surfaces are expressed, in accord with the available microscopy data. Calculations of defect energies at the (101) surface suggest that single Ti 3+ defects and neutral Ti 3+ -Li + pairs tend to segregate to the surface.

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“…[14,19]. pendent of the oxygen partial pressure will be observed, see e,g, The author would like to thank the persons for discussions, the help with the preparation of the thin films and their excellent technical assistance: Mrs. U. Lauer, Mr. J.…”

Section: (2 5 )mentioning

confidence: 98%

TiO₂ and Bi₂O₃ Thin Film Oxygen Sensor Materials

Nicoloso

1990

Ber Bunsenges Phys Chem

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Defect Chemistry / Electrical Properties / Interfaces 1 Sensors / Thin FilmsThe electrical conductivity of polycrystalline Ti02 and Bi203, deposited on sapphire substrate by various methods, has been determined as a function of the film thickness, the oxygen partial pressure and the temperature. As a rule, Ti02 films with d 5 30 nm are incoherent after heat treatment, thereby restricting the miniaturization of the planar sensor device. Larger films essentially behave like bulk material with fully ionized oxygen defects Vb (or Ti:' interstitials) as major intrinsic defects. In case of extrinsic p-type films, the conductivity contribution of the Ti02/sapphire substrate and Ti02/gas phase interfaces is clearly enhanced with respect to the bulk contribution, mainly due to segregation effects. Doubly ionized oxygen vacancies Vb and M$ defects (trivalent acceptor atoms at Ti-sites) appear to be the main intrinsic and extrinsic defects involved in the segregation process and in the oxygen exchange reaction. In contrast to TiO,, thin films of Bi203 react strongly with the substrate ultimately forming a new stable phase, A1,Bi209. Along with this structural change, the conductivity decreases by several orders of magnitude, classifying Bi2O3 as an unsuitable material for such thin film sensor devices.

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Electrical conductivity in non-stoichiometric titanium dioxide at elevated temperatures

Cited by 119 publications

References 36 publications

Electrical properties of polycrystalline TiO₂ at elevated temperatures. Electrical conductivity

Electrical properties of polycrystalline TiO₂ at elevated temperatures. Electrical conductivity

Defect Chemistry, Surface Structures, and Lithium Insertion in Anatase TiO₂

TiO₂ and Bi₂O₃ Thin Film Oxygen Sensor Materials

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Electrical conductivity in non-stoichiometric titanium dioxide at elevated temperatures

Cited by 119 publications

References 36 publications

Electrical properties of polycrystalline TiO2 at elevated temperatures. Electrical conductivity

Electrical properties of polycrystalline TiO2 at elevated temperatures. Electrical conductivity

Defect Chemistry, Surface Structures, and Lithium Insertion in Anatase TiO2

TiO2 and Bi2O3 Thin Film Oxygen Sensor Materials

Contact Info

Product

Resources

About

Electrical properties of polycrystalline TiO₂ at elevated temperatures. Electrical conductivity

Electrical properties of polycrystalline TiO₂ at elevated temperatures. Electrical conductivity

Defect Chemistry, Surface Structures, and Lithium Insertion in Anatase TiO₂

TiO₂ and Bi₂O₃ Thin Film Oxygen Sensor Materials