Electron microscope image contrast from small dislocation loops: III. Theoretical predictions for non-edge dislocation loops in a bcc crystal

Technical Report · Thu Feb 01 00:00:00 EST 1979

OSTI ID:5572749

Holmes, S M; Eyre, B L; English, C A; Perrin, R C

The theoretical study of image contrast from small finite dislocation loops in an isotropic bcc crystal, reported in Parts I and II has been extended to include non-edge loops. Computer image simulation has again been used to study the influence of loop normal, (n), Burger's vector, (b), diffraction vector, (g), and image plane normal, (z), on the distribution of black-white intensities in images from loops located in Layer 1, i.e. within 0.25 Epsilon (g) of the surface, where Epsilon (g) is the extinction distance for the diffracting vector (g). As before, the choice and range of parameters have been determined by interest in radiation damage in bcc molybdenum. The main conclusion from a survey of non-edge perfect loop images is that modifications are predicted to the images from edge loops on going to the non-edge configuration, but that in the majority of cases the scheme of image classification introduced for edge loops based on (g.b) is still appropriate.

• Research Organization: UKAEA Atomic Energy Research Establishment, Harwell
• OSTI ID: 5572749
• Report Number(s): AD-A-071656
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL DEFECTS
COMPUTERIZED SIMULATION
MOLYBDENUM
PHYSICAL RADIATION EFFECTS
CLASSIFICATION
ELECTRON MICROSCOPY
IMAGES
MONOCRYSTALS
CRYSTAL STRUCTURE
CRYSTALS
ELEMENTS
METALS
MICROSCOPY
RADIATION EFFECTS
REFRACTORY METALS
SIMULATION
TRANSITION ELEMENTS
360106* - Metals & Alloys- Radiation Effects