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Density and mobility of anti‐frenkel defects in SrF 2 crystals
Author(s) -
Bollmann W.
Publication year - 1980
Publication title -
kristall und technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0023-4753
DOI - 10.1002/crat.19800150214
Subject(s) - ion , enthalpy , frenkel defect , crystallography , conductivity , materials science , chemistry , analytical chemistry (journal) , crystallographic defect , atomic physics , thermodynamics , physics , organic chemistry , chromatography
By fitting the theoretically calculated temperature‐dependent conductivity σ to the measured dependencies log σ T ÷ 1/ T the following parameters have been determined: free formation enthalpy of anti‐Frenkel defects g AF = 2.05 eV – 6.35 kT ; mobilities of F − ion vacancies F ν −and interstitials F i − : v ν T = 600 exp (‐0.70 eV/ kT ) cm 2 K/Vs, v i T = 1.1 · 10 4 exp (‐0.93 eV/ kT ) cm 2 K/Vs. — The free association enthalpies of complexes consisting of single foreign ions (Sc 3+ , Y 3+ , La 3+ , Sm 3+ , Li + , K + , Na + , O − ) and the charge‐compensating defect were obtained. The vibration frequency of F − ions in the neighbourhood of F i −and F ν −is changed by a factor of 2.6 and 0.6, respectively.