Structures of the Stuffed Tridymite Derivatives, BaMSiO4 (M = Co, Zn, Mg)

Photoionization behavior of Eu2+-doped BaMgSiO4 long-persisting phosphor upon UV irradiation

“…The BaMgSiO 4 contains three crystallographically different barium sites labeled Ba1, Ba2 and Ba3 at 2a, 2b, and 2b Wickoff positions, respectively. The coordination number of Ba1, Ba2, and Ba3 sites is 9, 9 and 6, respectively: 9-coordinated Ba1 sites with Ba-O distances ranging from 2.78 to 2.99 Å , giving an average Ba-O distance of 2.89 Å ; 9-coordinated Ba2 sites with Ba-O distances ranging from 2.789 to 3.11 Å , giving an average Ba-O distance of 2.94 Å ; Ba3 sites are sixfold coordinated with identical Ba-O distances of 2.74 Å [22]. The detailed Ba-O distance data are listed in Table 2.…”

“…Recently, Peng et al [21] reported the observation of the spontaneous reduction of Eu 3+ to Eu 2+ in BaMgSiO 4 at high temperature. The compound BaMgSiO 4 belongs to the large structural family of stuffed tridymite (SiO 2 ) derivatives [22]. In BaMgSiO 4 , there are two tetrahedral groups, MgO 4 and SiO 4 , each SiO 4 is connected to four MgO 4 , and each MgO 4 is connected to four SiO 4 , and the two types of tetrahedrons are linked by corner sharing and build up the tridymite skeleton.…”

Multi color density photochromism in reduced tridymite BaMgSiO4 by wavelength of irradiation light

“…9) Later, as a result of progress in the X-ray diffraction (XRD) technique as well as the interest in the complex polymorphism of BaMgSiO 4 , more accurate crystal structures involving the determination of the unit cell parameters and volumes were established. 10) BaMgSiO 4 belongs to the stuffed tridymite structure with space group P6 3 , lattice parameters a = 0.91226, c = 0.87496 nm and volume 0.6306 nm 3 . In the tridymite structure of BaMgSiO 4 , the SiO 4 tetrahedrons are connected to each other by sharing corners and form three-dimensional tunnels, as shown in Fig.…”

Reduction from Eu3+ to Eu2+ in BaAl2O4:Eu phosphor prepared in an oxidizing atmosphere and luminescent properties of BaAl2O4:Eu

“…air or pure O 2 gas [3][4][5][6][7][8]. Though this last case is only applicable for a few special compounds with rigid three-dimensional (3-D) enclosed crystal structures, such as sulfates (BaSO 4 :Eu), phosphates (Ba 3 (PO 4 ) 2 :Eu), borophosphates (MBPO 5 [17][18][19][20][21], which exhibits the reduction from Eu 3+ to Eu 2+ when prepared in air [7], the similar phenomenon in BaAl 2 O 4 :Eu is anticipated and further confirmed by this work.…”