Synthesis of New Sr3RE2(Ge3O9)2 (RE=La, Y) cyclogermanates by liquid-phase precursor methods. (April 2017)

• Record Type: Journal Article
• Authors: Melkozerova, Marina A.; Lipina, Olga A.; Baklanova, Yana V.; Tyutyunnik, Alexander P.; Zubkov, Vladimir G.
• Is Part Of: Journal of physics and chemistry of solids. Volume 103(2017)
• Page Start: 76
• Page End: 81
• Publication Date: 2017-04
• Subjects: A. Optical materials -- C. X-ray diffraction -- D. Optical properties; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2016.12.007
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: New cyclogermanates Sr3 RE 2 (Ge3 O9 )2 ( RE =La, Y) with Ca3 Y2 (Si3 O9 )2 cyclosilicate structure type have been prepared by two liquid-phase precursor routes: the citrate and the Pechini methods. The phase composition, morphology and optical properties of the intermediate and final products have been characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectroscopy (DRS). The thermogravimetric (TGA) and differential thermal analyses (DTA) were used to study the thermal decomposition of the precursors. The powder XRD measurements indicate that the phase formation of Sr3 RE 2 (Ge3 O9 )2 ( RE =La, Y) (S.G. C 2 /c, Z=4) takes place after 20 h annealing at 800 °C. The DRS data revealed that the cyclogermanates are promising optical hosts. Highlights: Сyclogermanates with Ca3 Y2 (Si3 O9 )2 structure type have been prepared at the first time. The phase formation of Sr3 RE 2 (Ge3 O9 )2 ( RE =La, Y) been studied in detail. These cyclogermanates are promising phosphors.