Oxygen ion diffusion in single crystal SrTiO3

Paladino, Anna; Rubin, Lawrence G.; Waugh, J. S.

doi:10.1016/0022-3697(65)90168-x

Cited by 163 publications

(75 citation statements)

References 6 publications

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“…In fact, for rutile crystals (as grown) a reduction of the density of dislocations from 4 × 10 5 per cm 2 to about 1 × 10 5 per cm 2 was observed after thermal treatment at 1375 °C for 45 min [112]. Similar influence on the density of dislocations, namely the small lowering of their density [44,110], is known for a thermal treatment for SrTiO3 crystals. In principle, the reduction of the density of the edge dislocations in the matrix of the crystal can be realized by gliding or climbing of dislocations to the free surface.…”

Section: Annihilations or Multiplications Of Dislocationsmentioning

confidence: 66%

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Influence of Dislocations in Transition Metal Oxides on Selected Physical and Chemical Properties

et al. 2018

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Studies on dislocations in prototypic binary and ternary oxides (here TiO 2 and SrTiO 3 ) using modern TEM and scanning probe microscopy (SPM) techniques, combined with classical etch pits methods, are reviewed. Our review focuses on the important role of dislocations in the insulator-to-metal transition and for redox processes, which can be preferentially induced along dislocations using chemical and electrical gradients. It is surprising that, independently of the growth techniques, the density of dislocations in the surface layers of both prototypical oxides is high (10 9 /cm 2 for epipolished surfaces and up to 10 12 /cm 2 for the rough surface). The TEM and locally-conducting atomic force microscopy (LCAFM) measurements show that the dislocations create a network with the character of a hierarchical tree. The distribution of the dislocations in the plane of the surface is, in principle, inhomogeneous, namely a strong tendency for the bundling and creation of arrays or bands in the crystallographic <100> and <110> directions can be observed. The analysis of the core of dislocations using scanning transmission electron microscopy (STEM) techniques (such as EDX with atomic resolution, electron-energy loss spectroscopy (EELS)) shows unequivocally that the core of dislocations possesses a different crystallographic structure, electronic structure and chemical composition relative to the matrix. Because the Burgers vector of dislocations is per se invariant, the network of dislocations (with additional d 1 electrons) causes an electrical short-circuit of the matrix. This behavior is confirmed by LCAFM measurements for the stoichiometric crystals, moreover a similar dominant role of dislocations in channeling of the current after thermal reduction of the crystals or during resistive switching can be observed. In our opinion, the easy transformation of the chemical composition of the surface layers of both model oxides should be associated with the high concentration of extended defects in this region. Another important insight for the analysis of the physical properties in real oxide crystals (matrix + dislocations) comes from the studies of the nucleation of dislocations via in situ STEM indentation, namely that the dislocations can be simply nucleated under mechanical stimulus and can be easily moved at room temperature.

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Section: Annihilations or Multiplications Of Dislocationsmentioning

confidence: 66%

“…The determined density of dislocation is here 1.5 × 10 10 per cm 2 . The best results of a selective decoration of the end of dislocation lines for SrTiO3 crystals can be reached using HCl, HF or HNO3 etchants for short etching at 80-90 °C [44,45,68,[135][136][137]:…”

Section: Etch Pits Technique (Optical Sem and Afm Investigation)mentioning

confidence: 99%

Influence of Dislocations in Transition Metal Oxides on Selected Physical and Chemical Properties

et al. 2018

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“…Strontium titanate ceramics play an important role in technology, and the transport properties of these materials have thus been studied by several authors [1][2][3][4][5][6][7][8][9], including some efforts devoted to understand the effects of accepter dopants on the defect chemistry [10][11][12][13]. Renewed interest has been promoted by a range of potential applications including oxygen sensors [14], electrochemical membranes, and electrode materials for solid oxide fuel cells [13].…”

Section: Introductionmentioning

confidence: 99%

Combined effects of A-site deficiency and dopant content on the transport properties of Nb-doped strontium titanate

Abrantes

Labrincha

Frade

1997

Ionics

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Abstract. Strontium titanate based materials with A-site deficiency and Nb-additions were prepared to study the effects of these changes in composition on the transport properties and sinterability. X-ray diffraction was used for phase identification and to evaluate changes in the lattice parameters with composition. The dependence of the conductivity on the oxygen partial pressure was measured in the range 700-1000 ~ using an electrochemical oxygen pump to adjust the oxygen partial pressure in the furnace. Porous samples were used for this purpose to enhance the rate of exchange between the atmosphere and the samples. Changes in the composition have important effects on the relevant transport properties and also on the materials sinterability; this is especially true for Nb additions, which tend to suppress the p-type contribution under oxidizing conditions.

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“…Having the uncertainty of the measurements in mind, the value is in good agreement with the fit of oxygen concentration obtained by SIMS measurements at the same temperature (3.4 × 10 −10 m 2 s −1 at 600 • C). For comparison, oxygen diffusivity in nominally undoped STO is lower by several orders of magnitude, i.e., about 10 −15 m 2 s −1 at 600 • C as reported by Paladino et al (1965).…”

Section: Linking the Diffusion Data With Ionic Conductivitymentioning

confidence: 94%

Oxygen transport in epitaxial SrTiO3/SrTi1 − xFexO3 multilayer stacks

Schulz

Orland

Mehlmann

et al. 2017

J. Sens. Sens. Syst.

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Abstract. Nano-ionic materials made of strontium titanate (SrTiO 3 , STO) and solid solutions of strontium ferrite in STO (SrTi 1−x Fe x O 3 , STF) are grown on single crystalline STO substrates and characterized. Since STF exhibits an oxygen deficiency and, simultaneously, enables oxygen interstitial defects, a space charge area close to the STO | STF interface is present. Oxygen tracer diffusion experiments and impedance spectroscopy at temperatures from 500 to 700 • C and at oxygen partial pressure ranging from 10 −3 to 10 −23 bar confirm fast oxygen transport caused by enhanced ionic conductivity at the interface. There, an oxygen diffusion coefficient of 3.4 × 10 −10 m 2 s −1 at 600 • C and a p type conductivity of about 360 S m −1 at 700 • C are calculated. Such structures open new options in design of nano-ionic materials for oxygen sensors and energy conversion at temperatures lower than those of conventional materials such as yttrium-doped zirconia.

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Oxygen ion diffusion in single crystal SrTiO3

Cited by 163 publications

References 6 publications

Influence of Dislocations in Transition Metal Oxides on Selected Physical and Chemical Properties

Influence of Dislocations in Transition Metal Oxides on Selected Physical and Chemical Properties

Combined effects of A-site deficiency and dopant content on the transport properties of Nb-doped strontium titanate

Oxygen transport in epitaxial SrTiO<sub>3</sub>/SrTi<sub>1 − <i>x</i></sub>Fe<sub><i>x</i></sub>O<sub>3</sub> multilayer stacks

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Oxygen ion diffusion in single crystal SrTiO3

Cited by 163 publications

References 6 publications

Influence of Dislocations in Transition Metal Oxides on Selected Physical and Chemical Properties

Influence of Dislocations in Transition Metal Oxides on Selected Physical and Chemical Properties

Combined effects of A-site deficiency and dopant content on the transport properties of Nb-doped strontium titanate

Oxygen transport in epitaxial SrTiO&lt;sub&gt;3&lt;/sub&gt;/SrTi&lt;sub&gt;1 − &lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Fe&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; multilayer stacks

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Oxygen transport in epitaxial SrTiO<sub>3</sub>/SrTi<sub>1 − <i>x</i></sub>Fe<sub><i>x</i></sub>O<sub>3</sub> multilayer stacks