Structure refinement, ferroelectric domains and mechanical properties of Czochralski-grown Ca9La(VO4)7 and Ca10Li(VO4)7 single crystals

被引：0

作者：

Bedarev, V. A. ^{[1
]}

Kosmyna, M. B. ^{[2
]}

Mateychenko, P. V. ^{[2
]}

Merenkov, D. N. ^{[1
]}

Paszkowicz, W. ^{[3
]}

Poperezhai, S. N. ^{[1
]}

Fitch, A. ^{[4
]}

Romanowski, P. ^{[3
]}

Shekhovtsov, A. N. ^{[2
]}

机构：

[1] NAS Ukraine, B Verkin Inst Low Temp Phys & Engn, Nauky Ave 47, UA-61103 Kharkov, Ukraine

[2] NAS Ukraine, Inst Single Crystals, Nauky Ave 60, UA-61072 Kharkov, Ukraine

[3] Polish Acad Sci, Inst Phys, Aleja Lotnikow 32 46, PL-02668 Warsaw, Poland

[4] ESRF, CS40220, F-38043 Grenoble 9, France

来源：

FUNCTIONAL MATERIALS | 2024年 / 31卷 / 03期

关键词：

powder diffraction; orthovanadate; whitlockite; ferroelectric domain; crystal structure; RESOLUTION POWDER DIFFRACTION; DOUBLE VANADATES CA9R(VO4)(7); FRACTURE-TOUGHNESS; PHASE-TRANSITION; LA; PHOTOLUMINESCENCE; CA-9R(VO4)(7); GD; LN;

D O I：

10.15407/fm31.04.487

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Physical properties of whitlockite-type Ca3(VO4)2 orthovanadate can be modified by incorporation of isovalent or aliovalent cation substituents. In this paper, the features of the crystal structure of Ca9La(VO4)7 and Ca10Li(VO4)7 whitlockite-type crystals grown by the Czochralski method with substitution by aliovalent La or Li ions are studied. Refinement of the structure us- ing the Rietveld approach allowed us to determine the unit cell parameters and site occupancy. According to the data of polarization-optical studies, the formation of a strip-like ferroelectric domain structure with spontaneous polarization parallel to the third-order axis was established in the Ca9La(VO4)7 single crystal. It has been established that Ca10Li(VO4)7 is an antiferroelectric at room temperature. The correlations between Vickers hardness and fracture toughness values and the degree of crystal perfection are discussed.

引用

页码：487 / 494

页数：8