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HL: Halbleiterphysik
HL 7: Poster I
HL 7.16: Poster
Montag, 26. März 2001, 10:30–19:00, Rang S\ 3
Elastic properties of mercury chalcogenides: experiment and ab initio calculations — •A. Fleszar1, E.K.U. Gross1, W. Szuszkiewicz2, E. Dynowska2, W. Paszkowicz2, B. Morin3, M. Fischer3, and C. Lathe4 — 1Universität Würzburg — 2IF PAN, Warsaw, Poland — 3Université Pierre et Marie Curie, Paris, France — 4GeoForschungsZentrum Potsdam
The aim of this work is an experimental and theoretical characterization of selected elastic properties of mercury chalcogenides. Such a characterization is needed in order to interpret strain effects accompanying the epitaxial growth of these materials by MBE. From the measurements of ultrasonic wave velocities in HgSe monocrystals at hydrostatic pressures up to 0.35 GPa the values of the pressure dependence of the second order elastic constants, bulk modulus and its pressure derivative have been determined at room temperature. The parameters describing the HgSe equation of state have been obtained independently from high-pressure powder X-ray diffraction studies performed using a cubic-anvil press installed at the F2.1 synchrotron beamline in Hasylab (DESY). Elastic constant and bulk modulus values have also been obtained from first-principles calculations performed within the local density approximation using pseudopotentials and the mixed-basis method. Our present results, both, experimental and theoretical, are compared to literature data corresponding not only to HgSe but also to other mercury chalcogenides. Trends observed for II-VI metal chalcogenides families are shown and analyzed.