Regensburg 2016 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 27: Poster - Statistical Physics, Critical Phenomena, Brownian motion

DY 27.2: Poster

Tuesday, March 8, 2016, 18:15–21:00, Poster C

P-T-V equations of state for III-V compound semiconductors — •Alrik Stegmaier, Ulrich Vetter, and Hans Hofsäss — 2. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen

Equations of state (EoS) for solids are necessary for relating the state variables to each other and an important application is the description of the technologically important III-V compound semiconductors at different temperatures and pressures.

While many general EoS for solids exist, the introduction of a temperature dependence is not unique [1] and the materials considered here have negative thermal expansion coefficients at low temperatures [2], hampering a simple but accurate description. Further more, EoS are often not easily invertible [3] and several constraints have been suggested for isothermal EoS for solids that are not fullfilled by all formulations [4].

Here several EoS for III-V compound semiconductors are compared against experimental data and the results of ab-initio calculations. As a result a general P-T-V equation of state is proposed that is relatively accurate, simple, invertible and approximately fullfills the constraints reported in the literature for such an equation.

[1] R. E. Cohen et al., Am. Mineral., 85(4), 338-344, 2000

[2] G. Dolling and R. A. Cowley, Proc. Phys. Soc., 88, 463, 1965

[3] M. Etter and R. E. Dinnebier, J. Appl. Cryst., 47, 384-390, 2014

[4] P. K. Singh and A. Dwivedi, Indian J. Pure & Appl. Phys., 50, 734-738, 2012