Electronic structure and optical properties of ALa(9-x)Eu(x)(GeO4)(6)O-2 (A = Li, Na, K, Rb, Cs, La-1/3; x=0, 0.07) / Baklanova Yana V.,Lipina Olga A.,Enyashin Andrey N.,Baklanova Inna V.,Tyutyunnik Alexander P.,Surat Ludmila L.,Chufarov Alexander Yu.,Zubkov Vladimir G. // JOURNAL OF ALLOYS AND COMPOUNDS. - 2017. - V. 727, l. . - P. 390-397.

ISSN/EISSN:

0925-8388 / 1873-4669

Type:

Article

Abstract:

The new single-phase oxyapatites ALa(9)(GeO4)(6)O-2 and ALa(8.93)Eu(0.07)(GeO4)(6)O-2 (A = Li, Rb, space group P6(3)/m) are prepared using the ethylenediaminetetraacetic acid (EDTA) assisted process and the solid state method. Detailed characterization of the fine features of electronic structure within the families of oxyapatites ALa(9)(GeO4)(6)O-2 and ALa(8.93)Eu(0.07)(GeO4)(6)O-2 (A = Li, Na, K, Rb) has been performed using photoluminescence measurements and density functional theory (DFT) calculations. The trivalent europium ions may occupy two crystallographically nonequivalent sites (4f) and (6h) with the C-3 and C-s symmetry, respectively, and can be distinguished using the photoluminescence excitation on and the photoluminescence spectra from potassium and rubidium germanates, in contrast to those for lithium and sodium compounds. All the compounds should be semiconductors with wide direct band gaps of about 3.8 eV for alkali metal derivatives and about 3.2 eV for the vacancy-stabilized La-9.33(GeO4)(6)O-2 composition. The thermodynamic stability, the lattice parameters and the band gap value of CsLa9(GeO4)(6)O-2 not yet synthesized as a single phase have been qualified using DFT calculations. (C) 2017 Elsevier B.V. All rights reserved.

Author keywords:

Crystal structure; X-ray diffraction; Oxide materials; Luminescence; DFT calculations DENSITY-FUNCTIONAL THEORY; EU3+ ION; CRYSTAL; APATITES; SILICATE; YB; NALA9(GEO4)(6)O-2; LUMINESCENCE; TRANSITION; CERAMICS

DOI:

10.1016/j.jallcom.2017.08.144

Web of Science ID:

ISI:000412712900050

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	DEC 15
Publisher	ELSEVIER SCIENCE SA
Address	PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Language	English
EISSN	1873-4669
Keywords-Plus	DENSITY-FUNCTIONAL THEORY; EU3+ ION; CRYSTAL; APATITES; SILICATE; YB; NALA9(GEO4)(6)O-2; LUMINESCENCE; TRANSITION; CERAMICS
Research-Areas	Chemistry; Materials Science; Metallurgy \& Metallurgical Engineering
Web-of-Science-Categories	Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy \& Metallurgical Engineering
Author-Email	baklanovay@ihim.uran.ru
Funding-Acknowledgement	Russian Science Foundation {[}16-13-10111]
Funding-Text	The work was supported by the Russian Science Foundation (project No. 16-13-10111). The crystallographic study was carried out at the multipleeaccess center for Xeray structure analysis at the Institute of Solid State Chemistry, UB RAS (Ekaterinburg, Russia).
Number-of-Cited-References	42
Usage-Count-Last-180-days	4
Usage-Count-Since-2013	4
Journal-ISO	J. Alloy. Compd.
Doc-Delivery-Number	FJ4MH