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Enhanced nonlinear optical activity and Ca2+-conductivity in Са10.5-xPbx(VO4)7 ferroelectricsстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 13 февраля 2018 г.
- Авторы: Stefanovich Sergey Yu, Petrova Daria A., Morozov Vladimir A., Fortalnova Elena A., Belov Dmitry A., Deyneko Dina V., Barishnikova Oksana V., Belik Alexei A., Lazoryak Bogdan I.
- Журнал: Journal of Alloys and Compounds
- Номер: 735
- Год издания: 2018
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 1826
- Последняя страница: 1837
- DOI: 10.1016/j.jallcom.2017.11.172
- Аннотация: Са3(VO4)2-based compositions are considered as promising multifunctional materials combining ferroelectric, optical nonlinear, and Ca2+-ion conductive properties. Their ferroelectric Curie points stretch from minimal for β-Ca3(PO4)2 type compounds temperatures of about 800 K to very high. Investigated in this paper lead substitution for calcium is as a factor controlling ferroelectricity, ionic-conductivity and non-linear optical activity in Ca3(VO4)2-based materials. Polar phase containing powders and ceramics in Ca10.5-xPbx(VO4)7 system are synthesized for 0 ≤ x ≤ 9.5 by the solid state method, and structurally characterized with X-ray powder diffraction and transmission electron microscopy. Dielectric properties, differential thermal analysis and second harmonic generation (SHG) evidence that Ca10.5-xPbx(VO4)7solid solution(0 ≤ x ≤ 4.5) belongs to whitlockite-type ferroelectrics. SHG activity strongly increases with x up to its maximum at x = 4.5, where it has a record value among all studied before Ca3(XO4)2 related compounds (X=P,V). Ferroelectric Curie temperatures of Ca3(VO4)2 drops from its known value Tc = 1368 K (x = 0) to 770 K (x = 4.5). Crystal symmetry at Tc changes from R3c to R3¯c. After this, one more phase transition to the symmetry R m takes place, its temperature bringing down from 1387 K (x = 0) to 804 K (x = 4.5).Ferroelectric and non-ferroelectric phase transitions in the Са10.5-xPbx(VO4)7are separated by a broad interval ∆T = 20-50 K and both classified as first-order transformations going in the sequence: R3c↔R3¯c↔R3¯m.Structures of Са10.5-xPbx(VO4)7compositions with x = 0.5-4 were refined by the Rietveld method and peculiarities of the Pb2+cations distribution inthe M1 M2 and M3 sites of β-Ca3(PO4)2-type structure are discussed regarding the optical nonlinear, ferroelectric and ion-conductive properties. Manifold increased Ca2+- ionconductivity of Са10.5-xPbx(VO4)7 in vicinity of 1000 K at x = 4 4.5 in combination with their ferroelectric and optical nonlinear properties extends applicability of ion-exchange technologies to new promising materials.
- Добавил в систему: Дейнеко Дина Валерьевна