6533b839fe1ef96bd12a6359

RESEARCH PRODUCT

Ab initio simulations on AgCl(111) surface and AgCl(111)/α-Al2O3(0001) interface

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The defect chemistry and ionic transport properties of the AgCl(111)/α-Al 2 O 3 (0001) interface were consid by using ab initio slab calculations. These calculations were performed in the framework of plane-wave basis combined with the density functional theory (DFT), as implemented into the VASP computer code, and Gaus basis set combined with the Hartree-Fock method (CRYSTAL-98 code). We analyze the electron density distribu on the interface and the electrostatic potential distribution near the AgCl surface. The size of the silver ion is great to enter the corundum surface layer and to create excess silver ions in this way. This is in agreement the experiments on heterogeneous doping of AgCl revealing α-alumina to be inactive compared with γ-alum The energy to thermally create a vacancy in the first layer at the expense of an interstitial ion is large compared the bulk Frenkel energy. Despite the calculated low activation energy for vacancy transport in the layer (ΔH# s = 0.23 eV), the vacancy concentration will be too small to generate perceptible surface conducti The striking similarity of ΔH# s with the bulk value is due to the quite symmetrical arrangement of the consid interface.