X-ray diffraction study of the atomic interactions, anharmonic displacements and inner-crystal field in orthorhombic KNbO3

Stash, A.I.; Terekhova, E.O.; Ivanov, S.A.; Tsirelson, V.G.

Авторы: Stash Adam I., Terekhova Ekaterina O., Ivanov Sergey A., Tsirelson Vladimir G.
Журнал: Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials
Том: 77
Номер: 5
Год издания: 2021
Издательство: International Union of Crystallography
Местоположение издательства: United Kingdom
DOI: 10.1107/s2052520621006892
Аннотация: An X-ray diffraction study aimed at establishing the subtle details of theelectron density and anharmonicity of the atomic vibrations in a stoichiometricmonodomain single crystal of potassium niobate, KNbO3, has been conducted atroom temperature (orthorhombic ferroelectric phase Amm2). The cation andanion displacements obtained from the experiment are weakly anharmonicwithout any manifestation of structural disorder. The chemical bond andinteratomic interactions inside and between crystal substructures at the balanceof intracrystalline forces are characterized in detail. The role of each of the ionsin the formation of the ferroelectric phase was studied and the features of theelectron-density deformation in the niobium and oxygen substructures, and therole of each of them in the occurrence of spontaneous polarization areestablished. The position-space distribution of electrostatic and quantum forcesin KNbO3 is restored. It is emphasized that for the completeness of the analysisof the nature of the ferroelectric properties it is necessary to consider both staticand kinetic electronic factors, which are of a quantum origin. The experimentalresults and theoretical estimations by the Kohn–Sham calculation with periodicboundary conditions are in reasonable agreement, thus indicating the physicalsignificance of the findings of this study.
Добавил в систему: Сташ Адам Игаркович

	ИСТИНА	Войти в систему Регистрация
	ИСТИНА ИНХС РАН
	Главная Поиск Статистика О проекте Помощь

ИСТИНА

ИСТИНА ИНХС РАН

X-ray diffraction study of the atomic interactions, anharmonic displacements and inner-crystal field in orthorhombic KNbO3статья

Прикрепленные файлы