The Influence of Stoichiometric Defects on the Creep of Oxides with the Fluorite Structure

Seltzer, M. S.; Wilcox, B. A.; Clauer, A. H.

doi:10.1007/978-1-4615-8723-1_25

Cited by 5 publications

(5 citation statements)

References 14 publications

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“…The formation energy of an oxygen vacancy is calculated to be 4.42 eV. 7) The migration energies of nickel and oxygen vacancies are respectively calculated to be 2.65 and 1.56 eV, 26) which are consistent with experimentally measured values of 2.5 27,28) and 1.14-1.58 eV, 29,30) respectively. In our model, on the other hand, the difference in energy between the ideal surface and the metastable surface is 0.05 eV per surface atom (Fig.…”

Section: Formation/rupture Model Of Conductive Path On the Grain Surf...supporting

confidence: 79%

Switching mechanism in resistive random access memory by first-principles calculation using practical model based on experimental results

Moriyama

Yamasaki

Hida

et al. 2017

Jpn. J. Appl. Phys.

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For the practical use of resistive random access memory (ReRAM), many formation/rupture models of conductive paths are proposed. In this paper, we report both the probability of conductive path formation on grain surfaces and the marked drastic change in conductivity caused by a small number of atoms migrating on grain surfaces, determined by using experimental and calculation results complementarily. Experimental results of resistive switching operating modes suggest that resistance changes at grain boundaries, to which our calculation results can give an explanation. The energy for the conductive change from a low-resistance state to a high-resistance state is estimated to be about 0.05 eV per surface atom, which is much smaller than the formation and migration energies of vacancies (1.44–4.42 eV) and is comparable to the estimated temperature of the conductive path in the reset process.

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Section: Formation/rupture Model Of Conductive Path On the Grain Surf...supporting

confidence: 79%

Switching mechanism in resistive random access memory by first-principles calculation using practical model based on experimental results

Moriyama

Yamasaki

Hida

et al. 2017

Jpn. J. Appl. Phys.

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“…This picture may be over-simplified in that short-circuit diffusion and grain boundary diffusion may considerably upset the rate of reaction. Recent investigations on the growth of NiO on Ni by Rhines andCornel1 (1975) andSmeltzer (1974) tend to show that oxygen diffusing in grain boundaries in addition to normal cation diffusion is involved, but as yet these investigations have not been completed and the results have not been applied to A1203 or Crz03 scales.…”

Section: 1 Oxide Formationsmentioning

confidence: 99%

The oxidation of alloys

Wallwork¹

1976

Rep. Prog. Phys.

205

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A review of the principles governing alloy oxidation is presented together with the means by which practical oxidation-resistant alloys have been developed. The reactions involved are complex and involve acquiring data from many fields. Wagner developed the basic diffusional models for the formation of oxide scales, but these need to be expanded using detailed physical and metallurgical studies of the alloy phases, oxides and their defects, as well as the mode of scale formation and the structural relationships between alloy and oxide scale.At this time the engineering solutions have outstripped fundamental understanding, but an attempt is made to show how the development of oxidation theory has contributed to this effort by a term now referred to as 'informed empiricism'.There is no doubt that further fundamental studies will help improve present alloys in the continuing requirements of new atmospheres and higher temperatures.

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“…This classical description for the generation of the edge dislocations in metal or single oxides (binary oxides) cannot be one-to-one transferred on the situation in SrTiO 3, where the dislocations can possess a different chemical core (see e.g., [39]) which per se induces different local stress fields, and the interaction of edge dislocations with the same Burgers vector, cannot be simply interpreted [98].…”

Section: Arrangement Of Dislocationsmentioning

confidence: 99%

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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The Influence of Stoichiometric Defects on the Creep of Oxides with the Fluorite Structure

Cited by 5 publications

References 14 publications

Switching mechanism in resistive random access memory by first-principles calculation using practical model based on experimental results

Switching mechanism in resistive random access memory by first-principles calculation using practical model based on experimental results

The oxidation of alloys

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

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