Dielectrics fluorite

Dielectric screening. See Screening Dielectric susceptibility allolropic forms in SiOj, 275 from bond dipoles, 119f fluorites, 330f table, 331 higher order in field, 118ff ionic compounds 326ff dependence upon d,... 

The effect of RE +-F dipolar complexes on observed dielectric constants of RE-doped fluorites can be seen in Table 4. Polarizabilities and dielectric constants are elevated much more than would be anticipated from the introduction of the rare earth alone. For example, 1% ErFs substituted in BaF2 raises the dielectric constant by 19%, compared to an expected reduction of <0.5%. 

I.2.3. Recently, the application of impedance methods to disordered, condensed phases, such as organic polymers and glasses, warrants a general appreciation of the concepts involved. Dielectric loss measuranents are also important and are used extensively to study the energetics of relaxations of complex ionic defects, such as those found in the fluorite family of materials. 

Van Weperen et al. [1977] noted that in fluorite-structure materials the dielectric and ionic thermocurrent peaks broadened with increasing concentration of dipoles (for example Johnson et al. [1969]) and developed a theory of dipole-dipole interactions which predicted an almost Gaussian distribution of activation energies ... 

K. E. D. Wapenaar, H. G. Koekkoek, and J. van Turnhout [1982] Low-Temperature Ionic Conductivity and Dielectric Relaxation Phenomena in Fluorite-Type Solid Solutions, Solid State Ionics 7, 225-242. 

Denham P, Field GR, Morse PLR, Wilkinson GR (1970) Optical and dielectric properties and lattice dynamics of some fluorite structure ionic crystals. Proc Roy Soc London A 317 55-77... 

Dielectrics, semiconductors saturated by colour centres (e.g. quartz morion, dark fluorite)... 

Wapenaar, K.E.D., Ionic Conduction and Dielectric Loss in Fluorite-Type Solid Solutions, Ph.D. thesis, Utrecht University, The Netherlands, 1981. 

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