- Tytuł:
- Computer Modeling of Point Defects, Impurity Self-Ordering Effects and Surfaces in Advanced Perovskite Ferroelectrics
- Autorzy:
-
Borstel, G.
Kotomin, E. A.
Eglitis, R. I.
Heifets, E. - Tematy:
-
61.72.-y
71.15.-m
68.35.-p - Pokaż więcej
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Powiązania:
- https://bibliotekanauki.pl/articles/2014368.pdf Link otwiera się w nowym oknie
- Opis:
- The calculated optical properties of basic point defects - F-type centers and hole polarons - in KNbO$\text{}_{3}$ perovskite crystals are used for the interpretation of available experimental data. The results of quantum chemical calculations for perovskite KNb$\text{}_{x}$Ta$\text{}_{1-x}$O$\text{}_{3}$ solid solutions are presented for x=0, 0.125, 0.25, 0.75, and 1. An analysis of the optimized atomic and electronic structure clearly demonstrates that several nearest Nb atoms substituting for Ta in KTaO$\text{}_{3}$ - unlike Ta impurities in KNbO$\text{}_{3}$ - reveal a self-ordering effect, which probably triggers the ferroelectricity observed in KNb$\text{}_{x}$Ta$\text{}_{1-x}$O$\text{}_{3}$. Lastly, the (110) surface relaxations are calculated for SrTiO$\text{}_{3}$ and BaTiO$\text{}_{3}$ perovskites. The positions of atoms in 16 near-surface layers placed atop a slab of rigid ions are optimized using the classical shell model. Strong surface rumpling and surface-induced dipole moments perpendicular to the surface are predicted for both the O-terminated and Ti-terminated surfaces.
- Dostawca treści:
- Biblioteka Nauki
Artykuł