Berlin 2005 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 4: Poster

DF 4.7: Poster

Samstag, 5. März 2005, 08:30–16:30, Poster TU C

All-electron and pseudopotential calculations for PZT — •Igor Chaplygin, Sibylle Gemming, and Gotthard Seifert — Institut für Physikalische Chemie und Elektrochemie, TU Dresden, D-01062 Dresden

Perovskites of the PbZr_(1−x)Ti_xO₃ (PZT)type are the most important ferroelectric materials. The main aim of the current study, carried out in the framework of the DFG project "Ferroic functional elements: physical basics and concepts", was the comparison of the results obtained using a pseudopotential code (ABINIT) with those of precise full-electron calculations. The latter were obtained using the FPLO (full-potential local-orbital) calculation scheme. Both schemes are based on density functional theory in local-density approximation. The structural and electronic ground state properties of PZT were studied for x=0.00,0.25,0.50,0.75, and 1.00. Several types of the atomic pseudopotentials were tested. We found that the Teter extended norm-conserving pseudopotential gives most reliable results for all compositions, the lattice constant being slightly underestimated compared with that given by FPLO. The pseudopotential code was used for the optimization of the crystal structure. The resulting ground state crystal structures are in good agreement with experiment and other theoretical calculations.