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[ital Ab] [ital initio] calculation of thermodynamic properties of silicon

Journal Article · · Physical Review, B: Condensed Matter; (United States)
; ;  [1]
  1. School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States)

We present a fully [ital ab] [ital initio] calculation of the thermodynamic properties for silicon within the quasiharmonic approximation, making use of volume-dependent phonon frequencies obtained from pseudopotential local-density calculations. The temperature dependence of the thermal-expansion coefficient, specific heat (at constant volume), and other related quantities are studied. We confirm that the thermal-expansion coefficient behaves differently in three temperature regions: positive for temperature below 15 K, negative between 15 and 125 K, and positive again above 125 K. This finding agrees with experiment. The abnormal (negative) thermal-expansion coefficient at low temperatures is explained through a detailed study of mode Grueneisen parameters. Both specific-heat and thermal-expansion-coefficient values calculated are in excellent agreement with experiment up to a few hundred kelvin.

OSTI ID:
6731096
Journal Information:
Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:19; ISSN PRBMDO; ISSN 0163-1829
Country of Publication:
United States
Language:
English