Syntheses, Thermal Stability, and Structure Determination of the Novel Isostructural RBa₃B₉O₁₈ (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb)

Abstract

A novel borate compound YBa(3)B(9)O(18) has crystallized in a melt of BaYB(9)O(16). Single-crystal X-ray diffraction measurements reveal that YBa(3)B(9)O(18) adopts a hexagonal space group P6(3)/m with cell parameters of a = 7.1761(6) A and c = 16.9657(6) A. The structure is made up of the planar B(3)O(6) groups parallel to each other along the (001) direction, regular YO(6) octahedra, and irregular BaO(6) and BaO(9) polyhedra to form an analogue structure of beta-BaB(2)O(4). A series of isostructural borate compounds RBa(3)B(9)O(18) (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were prepared by powder solid-state reactions. The DTA and TGA curves of YBaB(9)O(16) show an obvious weight loss at about 955 degrees C associated with a decomposition into YBO(3), B(2)O(3), and YBa(3)B(9)O(18) due to its incongruent melting behavior. The DTA and TGA curves of YBa(3)B(9)O(18) show that it is chemically stable and a congruent melting compound. A comparison of the structures of YBa(3)B(9)O(18) and beta-BaB(2)O(4) is presented.

Luminescence and energy transfer of emission tunable phosphors YBa3B9O18:Ce3+, Tb3+

“…1, which are similar with each other and agree well with the calculated XRD pattern of YBa 3 B 9 O 18 in term of the crystal structure data of YBa 3 B 9 O 18 [11]. The diffractions for all samples are similar, indicating that all samples are of single phase.…”

“…Thus, Ce 3+ , Tb 3+ co-activated phosphors can achieve the tunable emission in visible region under UV excitation, which can match well with the UV chips-based w-LEDs [8]. Over the past few years, more and more researchers have focused on the luminescence properties of Ce 3+ , Tb 3+ co-activated inorganic phosphors [1,[8][9][10] In 2004, Li et al [11] first reported a kind of borate compound YBa 3 B 9 O 18 , the structure of which was characterized with a space group of P6 3 /m and was made up of planar B 3 O 6 groups parallel to each other along the (0 0 1) direction, regular REO 6 octahedra and irregular BaO 6 and BaO 9 polyhedra to form an analog structure of ␤-BaB 2 O 4 [11]. Recently, some works have been published on the luminescence properties of rare earth ion doped with YBa 3 B 9 O 18 [12,13].…”

Synthesis, crystal structure and X-ray excited luminescent properties of LuBa3B9O18

“…1 shows the powder X-ray diffraction patterns of YBa 3 B 9 O 18 , reported by Li et al [8], and LuBa 3 B 9 O 18 , respectively. By comparing the two patterns, we can conclude that the two compounds are isostructural.…”

“…In the past few years, several new rare earth (RE) and alkaline earth borates, such as RECa 4 O(BO 3 ) 3 [3], REBaB 9 O 16 [4], REBa 3 (BO 3 ) 3 [5][6][7] and REBa 3 B 9 O 18 [8] have been synthesized. The isomorphic compounds of REBa 3 B 9 O 18 were reported with the exception of La, Ce, Lu based compounds [8].…”

“…The isomorphic compounds of REBa 3 B 9 O 18 were reported with the exception of La, Ce, Lu based compounds [8]. Rare earth and alkaline earth borates have attracted so much attention because many of these compounds not only have been explored as new kinds of nonlinear optical materials themselves but also they have been widely used as hosts in preparation of self-frequency-doubling lasers and PDP phosphors [9][10][11][12][13].…”