Atomic-scale investigation of point defects and hydrogen-solute atmospheres on the edge dislocation mobility in alpha iron

The evaluation of the two dimensional projected atom column positions around a defect or an interface in an electronic ceramic, as it has been performed in numerous examples by (quantitative) conventional high-resolution electron microscopy (HRTEM), is often not sufficient to relate the electronic properties of the material to the structure of the defect. Information about point defects (vacancies, impurity atoms), and chemistry or bonding changes associated with the defect or interface is also required. Such complete characterization is a necessity for atomic scale interfacial or defect engineering to be attained.One instructive example where more than an image is required to understand the structure property relationships, is that of grain boundaries in Fe-doped SrTi03. Here, the different formation energies of point defects cause a charged barrier at the boundary, and a compensating space charge region around it. The sign and magnitude of the barrier depend very sensitively on the atomic scale composition and chemistry of the boundary plane.

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Atomistic study of hydrogen distribution and diffusion around a {112} edge dislocation in alpha iron

Acta Materialia ◽

10.1016/j.actamat.2008.04.011 ◽

2008 ◽

Vol 56 (15) ◽

pp. 3761-3769 ◽

Cited By ~ 88

Author(s):

Shinya Taketomi ◽

Ryosuke Matsumoto ◽

Noriyuki Miyazaki

Keyword(s):

Edge Dislocation ◽

Hydrogen Distribution ◽

Alpha Iron ◽

Atomistic Study ◽

And Diffusion

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Atomic-scale understanding on the physics and control of intrinsic point defects in lead halide perovskites

Applied Physics Reviews ◽

10.1063/5.0052402 ◽

2021 ◽

Vol 8 (3) ◽

pp. 031302

Author(s):

Jun Kang ◽

Jingbo Li ◽

Su-Huai Wei

Keyword(s):

Point Defects ◽

Atomic Scale ◽

Intrinsic Point Defects ◽

Halide Perovskites ◽

And Control ◽

Lead Halide

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Probing Semiconductor/Insulator Heterostructures Through Electron Spin Resonance of Point Defects: Interfaces, Interlayers, and Stress

MRS Proceedings ◽

10.1557/proc-984-0984-mm08-01 ◽

2006 ◽

Vol 984 ◽

Author(s):

A. Stesmans ◽

K. Clémer ◽

P. Somers ◽

V. V. Afanas'ev

Keyword(s):

Electron Spin Resonance ◽

Integrated Circuits ◽

Electron Spin ◽

Point Defects ◽

Atomic Scale ◽

Interface Quality ◽

Si Substrates ◽

Spin Resonance ◽

The Impact

AbstractElectron spin resonance (ESR) spectroscopy has become indispensable when it comes to the characterization on atomic-scale of structural, and correlated, electrical properties of actual semiconductor/insulator heterostructures. Through probing of paramagnetic point defects such as the Pb-type defects, E', and EX as a function of VUV irradiation and post deposition heat treatment, basic information as to the nature, quality, and thermal stability of the interface and interfacial regions can be established. This is illustrated by some specific examples of ESR analysis on contemporary Si/insulator structures promising for future developments in integrated circuits. First the impact of strain on the Si/SiO2 entity will be discussed. Through ESR analysis of thermally oxidized (111)Si substrates mechanically stressed in situ during oxidation, and tensile strained (100)sSi/SiO2 structures, it will be pointed out that in-plane tensile stress in Si can significantly improve the interface quality. Next, ESR results for stacks of (100)Si/SiOx/HfO2 and (100)Si/LaAlO3 are presented, revealing the potential to attain a high quality Si/SiO2 interface for the former and an abrupt, thermally stable interface for the latter.

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KIMERA: A Kinetic Montecarlo Code for Mineral Dissolution

Minerals ◽

10.3390/min10090825 ◽

2020 ◽

Vol 10 (9) ◽

pp. 825

Author(s):

Pablo Martin ◽

Juan J. Gaitero ◽

Jorge S. Dolado ◽

Hegoi Manzano

Keyword(s):

Monte Carlo ◽

Dissolution Rate ◽

Point Defects ◽

Open Source Software ◽

Kinetic Monte Carlo ◽

Object Oriented ◽

Mineral Dissolution ◽

Atomic Scale ◽

Mineral Structure ◽

Scientific Tool

KIMERA is a scientific tool for the study of mineral dissolution. It implements a reversible Kinetic Monte Carlo (KMC) method to study the time evolution of a dissolving system, obtaining the dissolution rate and information about the atomic scale dissolution mechanisms. KIMERA allows to define the dissolution process in multiple ways, using a wide diversity of event types to mimic the dissolution reactions, and define the mineral structure in great detail, including topographic defects, dislocations, and point defects. Therefore, KIMERA ensures to perform numerous studies with great versatility. In addition, it offers a good performance thanks to its parallelization and efficient algorithms within the KMC method. In this manuscript, we present the code features and show some examples of its capabilities. KIMERA is controllable via user commands, it is written in object-oriented C++, and it is distributed as open-source software.

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1001 Energy barrier for hydrogen diffusion around edge dislocation core in alpha iron

The Proceedings of The Computational Mechanics Conference ◽

10.1299/jsmecmd.2009.22.1 ◽

2009 ◽

Vol 2009.22 (0) ◽

pp. 1-2

Author(s):

Shinya TAKETOMI ◽

Ryosuke MATSUMOTO ◽

Noriyuki MIYAZAKI

Keyword(s):

Edge Dislocation ◽

Energy Barrier ◽

Hydrogen Diffusion ◽

Dislocation Core ◽

Alpha Iron

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Atomic Scale Modelling of the Primary Damage State of Irradiated UO2 Matrix

MRS Proceedings ◽

10.1557/proc-981-0981-jj01-01 ◽

2006 ◽

Vol 981 ◽

Author(s):

Laurent Van Brutzel ◽

Jean-Paul Crocombette

Keyword(s):

Grain Boundary ◽

Point Defects ◽

Large Scale ◽

Recoil Nucleus ◽

Atomic Scale ◽

Damage State ◽

Stable Clusters ◽

Scale Modelling ◽

Primary Damage ◽

Dynamics Simulations

AbstractLarge scale classical molecular dynamics simulations have been carried out to study the primary damage state due to a-decay self irradiation in UO2 matrix. Simulations of energetic displacement cascades up to the realistic energy of the recoil nucleus at 80 keV provide new informations on defect production, their spatial distribution and their clustering. The discrepancy with the classical linear theory NRT (Norton-Robinson-Torrens) law on the creation of the number of point defects is discussed. Study of cascade overlap sequence shows a saturation of the number of point defects created as the dose increases. Toward the end of the overlap sequence, large stable clusters of vacancies are observed. The values of athermal diffusion coefficients coming from the ballistic collisions and the additional point defects created during the cascades are estimated from these simulations to be, in all the cases, less than 10-26 m2/s. Finally, the influence of a grain boundary of type Sigma5 is analysed. It has been found that the energy of the cascades are dissipated along the interface and that most of the point defects are created at the grain boundary.

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