Computer modeling of point defects in perovskite crystals
Autor(en): | Eglitis, RI Kotomin, EA Borstel, G Vikhnin, VS |
Stichwörter: | 1ST-PRINCIPLES; ABO(3) perovskites; DISPLACEMENT; FERROELECTRICS; HARTREE-FOCK CALCULATIONS; KNBO3; Materials Science; Materials Science, Multidisciplinary; MULLER PHASE; ORIGIN; Physics; Physics, Condensed Matter; point defects; POLAR MICRODOMAINS; SEMIEMPIRICAL CALCULATIONS; solid solutions; TRANSFER VIBRONIC EXCITONS | Erscheinungsdatum: | 2002 | Herausgeber: | TAYLOR & FRANCIS LTD | Enthalten in: | FERROELECTRICS | Band: | 268 | Startseite: | 59 | Seitenende: | 64 | Zusammenfassung: | The results of calculations for mixed perovskite KNbxTa1-xO3 (KTN) solid solutions are presented and discussed. The semiempirical method of the intermediate neglect of differential overlap (INDO) based on the Hartree-Fock formalism predicts magnitudes of the Nb off-center displacements which are in agreement with EXAFS data. Results are compared with ab initio FP-LMTO first-principles calculations. The latter formalism and the semiempirical INDO methods are combined for the study of hole and electron polarons in perovskites. We calculated the defect migration energies using INDO method and classical shell model (SM) for the cubic phase of the KNbO3 . The migration energies for the O vacancy obtained by these methods are reasonably close and agree with the only experimental estimate available of 1 eV. |
Beschreibung: | 10th International Meeting on Ferroelectricity, MADRID, SPAIN, SEP 03-07, 2001 |
ISSN: | 00150193 | DOI: | 10.1080/00150190211081 |
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geprüft am 09.06.2024