Dresden 2011 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 12: Postersitzung I

MM 12.24: Poster

Montag, 14. März 2011, 17:30–19:00, P5

Heat capacity of aluminum nitride phases from ab initio calculations — •Steve Schmerler and Jens Kortus — TU Bergakademie Freiberg, Institut für Theoretische Physik, Leipziger Str. 23, 09599 Freiberg, Germany

The ability to calculate thermodynamical material properties on ab initio level is an important preliminary for the accurate prediction of phase diagrams.

We present results on the heat capacity of the wurtzite and rock-salt phases of aluminum nitride. The isochoric heat capacity C_V is obtained from harmonic phonon calculations using density functional perturbation theory. In the quasi-harmonic approximation, the isobaric heat capacity C_p is then obtained from C_V via the thermal expansion coefficient. The latter is calculated (i) directly from the mode Grüneisen parameters using phonon calculations at several volumes and (ii) estimated from molecular dynamics.

We would like to thank the DFG for financial support within the DFG Priority Program 1236: Strukturen und Eigenschaften von Kristallen bei extrem hohen Drücken und Temperaturen