POINT DEFECT - DISLOCATION INTERACTION IN MgO

STUDY OF DISLOCATION - POINT DEFECTS INTERACTION IN MgO SINGLE CRYSTALS BY INTERNAL FRICTION

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

2014 We consider a lattice dynamics model of a straight screw dislocation moving in a simple cubic lattice with nearest-neighbour « snapping bonds ». The effect on the lattice of the dislocation motion is described by a dynamic source-force, or Kanzaki-force, and the lattice response by the phonon Green’s function. A random array of isotopic substitutional point defects is introduced, and the a...

Morphology and optical properties of MgO thin films on Mo(001)

Thin MgO films with a nominal thickness ranging between 1 to 60 ML have been grown on a Mo(001) surface. The film morphology was studied by LEED and STM, revealing the presence of a coincidence pattern with the Mo support in the low coverage regime, a dislocation network at medium thickness and a rather flat and defect-poor MgO surface for thicker layers. The MgO optical properties were investi...

The Motion of Dislocations in Irradiated Materials

The motion of dislocations in irradiated materials has unique features that are not seen in unirradiated materials undergoing plastic deformation. In the present work, we show dislocation dynamics studies that reveal the single and collective aspects of dislocation motion in materials under displacement cascade damage. First, we investigate the dynamics of dislocation interaction with irradiati...

Dislocation Mechanisms for Shock-Induced Hot Spots

Crystal dislocations provide the ultimate source of localized damage enhancement within solid materials. Vortices are the dislocation counterparts within liquids and gases. For energetic crystals, tubular holes might run along the pre-existent dislocation line lengths and act as shock-induced "in-situ" hot spots. Beyond this consideration, nearly invisible clouds of dislocations are possibly ge...