1. A Calorimetric Study Assisted with First Principle Calculations of Specific Heat for Si-Ge Alloys within a Broad Temperature Range
- Author
-
Qing Wang, Ming-Xing Li, De-Lu Geng, BingBo Wei, and Hai-Peng Wang
- Subjects
Bulk modulus ,Materials science ,Transition temperature ,General Physics and Astronomy ,Thermodynamics ,02 engineering and technology ,Calorimetry ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,01 natural sciences ,Thermal expansion ,Negative thermal expansion ,0103 physical sciences ,Melting point ,Isobaric process ,010306 general physics ,0210 nano-technology - Abstract
Calorimetric measurements are performed to determine the specific heat of Si-x at.% Ge (where x = 0, 10, 30, 50, 70, 90 and 100) alloys within a broad temperature range from 123 to 823 K. The measured specific heat increases dramatically at low temperatures, and the composition dependence of specific heat is evaluated from the experimental results. Meanwhile, the specific heat at constant volume, the thermal expansion, and the bulk modulus of Si and Ge are investigated by the first principle calculations combined with the quasiharmonic approximation. The negative thermal expansion is observed for both Si and Ge. Furthermore, the isobaric specific heat of Si and Ge is calculated correspondingly from 0 K to their melting points, which is verified by the measured results and accounts for the temperature dependence in a still boarder range.
- Published
- 2018