An Analysis of Thermal Expansion and Melting in Alkali Halides

  • L. L. Boyer


An analysis of thermal expansion and melting is presented which predicts, to within a reasonable accuracy expected from the approximations of the theory, the melting temperature (T M ) and the thermal expansion up to and including the discontinuity at T M . Based on first-principles equation of state calculations for alkali halides, the lattice constant is shown to have a (T c — T)1/2 behavior in the high temperature limit. This implies that the thermal expansion coefficient diverges as TT c and hence the isothermal bulk modulus goes to zero at T c. A least squares analysis of published thermal expansion data for NaCl using this analytic form suggests that T M T c ⪝ 1.1 T M , but more accurate data is needed to fix T c within this range.


Thermal Expansion Lattice Constant Alkali Halide High Temperature Limit Thermal Expansion Behavior 
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Copyright information

© Purdue Research Foundation 1982

Authors and Affiliations

  • L. L. Boyer
    • 1
  1. 1.Naval Research LaboratoryUSA

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