Premium
Activation Volume for Vacancy Motion in Calcium Fluoride
Author(s) -
Fontanella J. J.,
Wintersgill M. C.,
Andeen C.
Publication year - 1980
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220970135
Subject(s) - vacancy defect , compressibility , volume (thermodynamics) , atmospheric temperature range , sodium , materials science , dielectric , ion , thermodynamics , calcium , chemistry , condensed matter physics , mineralogy , crystallography , metallurgy , physics , organic chemistry , optoelectronics
The audio frequency complex dielectric constant for sodium doped calcium fluoride is measured at pressures up to 0.4 GPa over the temperature range 240 to 270 K and at zero pressure over the temperature range 5.5 to 400 K. Consequently, the reorientation of a nearest‐neighbor vacancy around a substitutional sodium ion is studied. The activation volume for the motion is found to be (1.73 ± 0.1) cm 3 /mol. It is argued that this value should be similar to the migration volume for “free” vacancies. The compressibility of the activation volume is found to be forty times the compressibility of the host lattice. Finally, a large negative thermal expansion coefficient is found for the activation volume for vacancy motion.