Radiation Defects in CaF2-CaO Crystals

Growth and Characterization of Doped CaF2 Crystals

Probing electron induced defects in CaF2 by photothermal displacement

The surface displacement technique is used to measure the temperature and frequency dependence of the periodic expansion of a CaF2-surface subject to a modulated focused beam of lkeV electrons. Theoretical models are presented for a prediction of the observed phenomena based on thermal transport and defect lifetime effects. The use of such investigations for the study of thermal and non-thermal...

-module defects in crystals

An analysis is presented of the new types of defects that can appear in crystalline structures where the positions of the atoms and the unit cell belong to the same {\bb Z}-module, i.e. are irrational projections of an N > 3-dimensional (N-D) lattice Λ as in the case of quasicrystals. Beyond coherent irrationally oriented twins already discussed in a previous paper [Quiquandon et al. (2016). Ac...

Defects in Nematic Liquid Crystals

Defects in liquid crystals are discontinuities in order parameter. In nematic liquid crystals (NLC) two types of stable defects exist: disclination lines and point defects. Defects formation depends on isotropic to nematic phase transition while their stability depends strongly on confining surface properties, surface geometry and presence of external field. Classical Frank’s model of director ...

Nematic Liquid Crystals: Defects

There are two types of defects in the uniaxial nematic F phase: line defects (disclinations) and point defects (hedgehogs and boojums). These are reviewed at three levels: (i) experimental observations; (ii) topological classification; and (iii) curvature elasticity. The reader is referred to the textbooks on liquid crystals (Chandrasekhar 1992, de Gennes and Prost 1993), defects (Kltman 1983),...