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Title: Graded Interface Models for more accurate Determination of van der Waals-London Dispersion Interactions across Grain Boundaries

Abstract

Attractive van der Waals V London dispersion interactions between two half crystals arise from local physical property gradients within the interface layer separating the crystals. Hamaker coefficients and London dispersion energies were quantitatively determined for 5 and near- 13 grain boundaries in SrTiO3 by analysis of spatially resolved valence electron energy-loss spectroscopy (VEELS) data. From the experimental data, local complex dielectric functions were determined, from which optical properties can be locally analysed. Both local electronic structures and optical properties revealed gradients within the grain boundary cores of both investigated interfaces. The obtained results show that even in the presence of atomically structured grain boundary cores with widths of less than 1 nm, optical properties have to be represented with gradual changes across the grain boundary structures to quantitatively reproduce accurate van der Waals V London dispersion interactions. London dispersion energies of the order of 10% of the apparent interface energies of SrTiO3 were observed, demonstrating their significance in the grain boundary formation process. The application of different models to represent optical property gradients shows that long-range van der Waals V London dispersion interactions scale significantly with local, i.e atomic length scale property variations.

Authors:
 [1];  [2];  [3];  [4];  [5];  [5]
  1. ORNL
  2. University of Pennsylvania
  3. DuPont Company
  4. Deconvolution and Entropy Consulting
  5. National Institutes of Health
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1003724
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 74; Journal Issue: 20; Journal ID: ISSN 1098--0121
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DIELECTRIC MATERIALS; ELECTRONIC STRUCTURE; ELECTRONS; ENERGY-LOSS SPECTROSCOPY; GRAIN BOUNDARIES; OPTICAL PROPERTIES; VALENCE; graded interface; london dispersion force

Citation Formats

van Benthem, Klaus, Tan, Guolong, French, Roger H, DeNoyer, Linda K, Podgornik, Rudolf, and Parsegian, V Adrian. Graded Interface Models for more accurate Determination of van der Waals-London Dispersion Interactions across Grain Boundaries. United States: N. p., 2006. Web. doi:10.1103/PhysRevB.74.205110.
van Benthem, Klaus, Tan, Guolong, French, Roger H, DeNoyer, Linda K, Podgornik, Rudolf, & Parsegian, V Adrian. Graded Interface Models for more accurate Determination of van der Waals-London Dispersion Interactions across Grain Boundaries. United States. doi:10.1103/PhysRevB.74.205110.
van Benthem, Klaus, Tan, Guolong, French, Roger H, DeNoyer, Linda K, Podgornik, Rudolf, and Parsegian, V Adrian. Sun . "Graded Interface Models for more accurate Determination of van der Waals-London Dispersion Interactions across Grain Boundaries". United States. doi:10.1103/PhysRevB.74.205110.
@article{osti_1003724,
title = {Graded Interface Models for more accurate Determination of van der Waals-London Dispersion Interactions across Grain Boundaries},
author = {van Benthem, Klaus and Tan, Guolong and French, Roger H and DeNoyer, Linda K and Podgornik, Rudolf and Parsegian, V Adrian},
abstractNote = {Attractive van der Waals V London dispersion interactions between two half crystals arise from local physical property gradients within the interface layer separating the crystals. Hamaker coefficients and London dispersion energies were quantitatively determined for 5 and near- 13 grain boundaries in SrTiO3 by analysis of spatially resolved valence electron energy-loss spectroscopy (VEELS) data. From the experimental data, local complex dielectric functions were determined, from which optical properties can be locally analysed. Both local electronic structures and optical properties revealed gradients within the grain boundary cores of both investigated interfaces. The obtained results show that even in the presence of atomically structured grain boundary cores with widths of less than 1 nm, optical properties have to be represented with gradual changes across the grain boundary structures to quantitatively reproduce accurate van der Waals V London dispersion interactions. London dispersion energies of the order of 10% of the apparent interface energies of SrTiO3 were observed, demonstrating their significance in the grain boundary formation process. The application of different models to represent optical property gradients shows that long-range van der Waals V London dispersion interactions scale significantly with local, i.e atomic length scale property variations.},
doi = {10.1103/PhysRevB.74.205110},
journal = {Physical Review B},
issn = {1098--0121},
number = 20,
volume = 74,
place = {United States},
year = {2006},
month = {1}
}