Jianlong Huang,Chengfa Wu,Jianbang Chen,Zhiyong Guo,Wenjuan Ma,Feng Yu,Bin Dai
A new rare-earth borate Na3YB8O15 was fabricated by the flux method. The compound crystallizes in the P group, and shows a three-dimensional network built by [B8O17] fundamental building blocks (FBBs) with [NaO6], [NaO7], and [YO7] polyhedra. The [B8O17] FBBs are composed of five planar BO3 and three BO4 tetrahedra and connected via corner-sharing to construct a unique one-dimensional (1D) [B8O15]∞ infinity chain that is observed for the first time in the Na2O–Y2O3–B2O3 system compound, enriching the structural diversity of rare-earth borate. The title compound exhibits a short ultraviolet (UV) cutoff edge of ∼195 nm and a wide experimental band gap of 5.50 eV. DFT calculations indicate that Na3YB8O15 is a direct band gap compound with a calculated GGA band gap of 5.14 eV, and the band gap is mainly determined by B 2p and O 2p orbitals. The results update the phase diagram of Na2O–Y2O3–B2O3 and enrich the diversity of rare-earth metal borates.
Dongdong Xu,Fangfang Zhang,Yanzhou Sun,Zhihua Yang,Binghua Lei,Lili Liu,Shilie Pan
A new rare-earth borate LiRb2LaB2O6 (LB-1) has been synthesized using a high-temperature solution method. Interestingly, it shares its topological structure with the famous porous material MOF-5, which is formed from Zn4O(BDC)3 (BDC = 1,4-benzenedicarboxylate). The nodes [OZn4] and organic linkers [BDC] of MOF-5 are carefully substituted with La3+ rare-earth cations and the inorganic linkers [BO3] and [LiO4], respectively, in order to construct a pure inorganic open framework. LB-1 exhibits good thermal and water stability. Moreover, it possesses a short cut-off edge (<190 nm) and moderate birefringence (exp. 0.040@589.5 nm, cal. 0.038@589.5 nm). Further insights into the cut-off edge were given by first-principles calculations. The factors that influence the birefringence of LB-1 were discussed in view of the spatial arrangement of the [BO3] anionic groups.
Juhe Liu,Yuwei Chen,Mengran Sun,Wenhao Liu,Xianghe Meng,Jiyong Yao
A new complex rare earth borate K7PbLu2B15O30 was prepared by the spontaneous crystallization method. K7PbLu2B15O30 is crystallized in the chiral trigonal space group R32 with cell parameters a = b = 13.0893(3) Å, c = 15.2379(6) Å, α = β = 90°, γ = 120°, and Z = 3. The basic structure of the crystal can be seen as composed of B5O10 groups and LuO6 polyhedra sharing oxygen atoms, while K+ and Pb2+ fill the space to balance the charge. The UV transmission cut-off edge of K7PbLu2B15O30 was less than 300 nm, and the powder SHG response was roughly 1.1 times that of KDP. Furthermore, a first-principles analysis was performed to see more about the relationship between the crystal structure and optical characteristics.