Lattice dynamics of crystals with extended point defects

1969 ◽  
Vol 7 (18) ◽  
pp. 1371-1377 ◽  
Author(s):  
J. Oitmaa ◽  
A.A. Maradudin
Keyword(s):  
Point Defects ◽  
Lattice Dynamics ◽  
Extended Point

A lattice-dynamics model of the interaction of a dislocation with point defects

1984 ◽  
Vol 45 (8) ◽  
pp. 1337-1345 ◽  
Author(s):  
J.A. Caro ◽  
N. Glass
Keyword(s):  
Point Defects ◽  
Lattice Dynamics ◽  
Dynamics Model

scholarly journals Extended Point Defects in Crystalline Materials: Ge and Si

2013 ◽  
Vol 110 (15) ◽  
Author(s):  
N. E. B. Cowern ◽  
S. Simdyankin ◽  
C. Ahn ◽  
N. S. Bennett ◽  
J. P. Goss ◽  
...  
Keyword(s):  
Point Defects ◽  
Crystalline Materials ◽  
Extended Point

Influence of Force-Constant Changes on the Lattice Dynamics of Cubic Crystals with Point Defects

1968 ◽  
Vol 165 (3) ◽  
pp. 1011-1018 ◽  
Author(s):  
Philip D. Mannheim
Keyword(s):  
Force Constant ◽  
Point Defects ◽  
Lattice Dynamics ◽  
Cubic Crystals

Modeling of the lattice dynamics in MgO crystals with point defects in different charge states

2005 ◽  
Vol 368 (1-4) ◽  
pp. 287-296 ◽  
Author(s):  
V.G. Mazurenko ◽  
A.B. Sobolev ◽  
A.N. Kislov ◽  
K.N. Korzov ◽  
V.V. Kulyashov ◽  
...  
Keyword(s):  
Point Defects ◽  
Lattice Dynamics ◽  
Charge States

Vibrational resonance modes due to extended point defects

1970 ◽  
Vol 8 (1) ◽  
pp. 57-60 ◽  
Author(s):  
J. Oitmaa
Keyword(s):  
Point Defects ◽  
Vibrational Resonance ◽  
Resonance Modes ◽  
Extended Point

Microstructural Evolution in Reduced TiO2

1981 ◽  
Vol 39 ◽  
pp. 74-75
Author(s):  
W. T. Donlon ◽  
S. Shinozaki ◽  
E. M. Logothetis ◽  
W. Kaizer
Keyword(s):  
Microstructural Evolution ◽  
Point Defects ◽  
Extended Defects ◽  
Small Deviations ◽  
Controlled Atmospheres ◽  
Limited Solubility ◽  
Thin Foils ◽  
Heat Treated ◽  
Porous Polycrystalline ◽  
Crystallographic Shear

Since point defects have a limited solubility in the rutile (TiO2) lattice, small deviations from stoichiometry are known to produce crystallographic shear (CS) planes which accomodate local variations in composition. The material used in this study was porous polycrystalline TiO2 (60% dense), in the form of 3mm. diameter disks, 1mm thick. Samples were mechanically polished, ion-milled by conventional techniques, and initially examined with the use of a Siemens EM102. The electron transparent thin foils were then heat-treated under controlled atmospheres of CO/CO2 and H2 and reexamined in the same manner.The “as-received” material contained mostly TiO2 grains (∼5μm diameter) which had no extended defects. Several grains however, aid exhibit a structure similar to micro-twinned grains observed in reduced rutile. Lattice fringe images (Fig. 1) of these grains reveal that the adjoining layers are not simply twin related variants of a single TinO2n-1 compound. Rather these layers (100 - 250 Å wide) are alternately comprised of stoichiometric TiO2 (rutile) and reduced TiO2 in the form of Ti8O15, with the Ti8O15 layers on either side of the TiO2 being twin related.

Simulated Dark-Field Electron Micrographs of Point Defects and Organometallics

1975 ◽  
Vol 33 ◽  
pp. 200-201
Author(s):  
William Krakow
Keyword(s):  
Electron Micrographs ◽  
Point Defects ◽  
Structure Determination ◽  
Atomic Structure ◽  
Image Interpretation ◽  
Dark Field ◽  
Field Electron ◽  
Dark Field Microscopy ◽  
Dark Field Electron

Tilted beam dark-field microscopy has been applied to atomic structure determination in perfect crystals, several synthesized molecules with heavy atcm markers and in the study of displaced atoms in crystals. Interpretation of this information in terms of atom positions and atom correlations is not straightforward. Therefore, calculated dark-field images can be an invaluable aid in image interpretation.

Defects in Crystals

1968 ◽  
Vol 26 ◽  
pp. 244-245
Author(s):  
Kenneth R. Lawless
Keyword(s):  
Electron Microscope ◽  
Point Defects ◽  
Surface Defects ◽  
Chemical Properties ◽  
Material Point ◽  
Crystal Defects ◽  
Defects In Crystals ◽  
Irradiation Effects ◽  
Normal Lattice ◽  
Line Defects

One of the most important applications of the electron microscope in recent years has been to the observation of defects in crystals. Replica techniques have been widely utilized for many years for the observation of surface defects, but more recently the most striking use of the electron microscope has been for the direct observation of internal defects in crystals, utilizing the transmission of electrons through thin samples.Defects in crystals may be classified basically as point defects, line defects, and planar defects, all of which play an important role in determining the physical or chemical properties of a material. Point defects are of two types, either vacancies where individual atoms are missing from lattice sites, or interstitials where an atom is situated in between normal lattice sites. The so-called point defects most commonly observed are actually aggregates of either vacancies or interstitials. Details of crystal defects of this type are considered in the special session on “Irradiation Effects in Materials” and will not be considered in detail in this session.

Sign in / Sign up

Export Citation Format

Share Document