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RESEARCH PRODUCT

Theoretical Modelling of the Energy Surface (001) and Topology of CaZrO3 Perovskite

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I present the results of ab initio calculations of surface relaxations, rumplings, energetics, optical band gaps, and charge distribution for the CaZrO3 (001) surfaces using computer code CRYSTAL and a hybrid description of exchange and correlation. I consider both CaO and ZrO2-terminations of the CaZrO3 (001) surface. On the both CaO and ZrO2-terminated CaZrO3 (001) surfaces, I find that all upper and third layer atoms relax inwards, whereas all second layer atoms relax upwards. I predict a considerable increase of the Zr-O chemical bond covalency (0.102e) near the ZrO2-terminated CaZrO3 (001) surface relative to the CaZrO3 bulk (0.086e). My calculated CaO (0.87 eV) and ZrO2-terminated (1.33 eV) CaZrO3 (001) surface energies are considerably smaller than another ABO3 perovskite polar (011) and (111) surface energies. The calculated optical band gaps near the CaO (5.00 eV) and ZrO2-terminated (5.22 eV) CaZrO3 (001) surfaces are considerably reduced with respect to the bulk band gap (5.40 eV).