High-pressure synthesis and characterization of the first cerium fluoride borate CeB2O4F

Abstract

CeB2O4F is the first cerium fluoride borate, which is exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO3]3− groups. This new cerium fluoride borate was synthesized under high-pressure/high-temperature conditions of 0.9 GPa and 1450 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with eight formula units and the lattice parameters a=821.63(5), b=1257.50(9), c=726.71(6) pm, V=750.84(9) Å3, R1=0.0698, and wR2=0.0682 (all data). The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO3]3− groups. Furthermore, IR spectroscopy, Electron Micro Probe Analysis and temperature-dependent X-ray powder diffraction measurements were performed.

Borates: A Rich Source for Optical Materials

“…After that, more borates, including α-LiBO 2 , SrB 2 O 4 , REMoBO 6 (RE = Ce, La), UB 2 O 6 , NaBeB 3 O 6 , and CeB 2 O 4 F with the structural motifs similar to CaB 2 O 4 are discovered experimentally. The CeB 2 O 4 F series are obtained under high-pressure driven conditions, showing the first and sole F-containing borate with such structural motifs .…”

“…After that, more borates, including α-LiBO 2 , SrB 2 O 4 , REMoBO 6 (RE = Ce, La), UB 2 O 6 , NaBeB 3 O 6 , and CeB 2 O 4 F with the structural motifs similar to CaB 2 O 4 are discovered experimentally. The CeB 2 O 4 F series are obtained under high-pressure driven conditions, showing the first and sole F-containing borate with such structural motifs . Different from the coplanar configurations in CaB 2 O 4 , the 1 [BO 2 ] ∞ chains in CeB 2 O 4 F show a wave modulation with the formal wavelength of λ = a , and the linkage of individual [BO 3 ] triangles occurs by O­(2,3) atoms, whereas the O­(1,4) atoms locate on the terminal positions of these chains .…”

High-pressure Synthesis and Characterization of the Rare-earth Fluoride Borate LaB2O4F

“…61) Fig. 2 (color [26], and the alkali metal borate α-LiBO 2 [27 -29] Tables 4 and 5 show the interatomic distances of LaB 2 O 4 F. For a detailed description of the structure, the reader is referred to the paper of the isotypic compound CeB 2 O 4 F [6]. In this work, we briefly compare the isotypic phases REB 2 O 4 F (RE = La, Ce) and the results of the DFT calculation.…”

“…A closer look into the class of rare-earth fluoride borates shows various compounds for the rare-earth cations Pr 3+ -Nd 3+ and Sm 3+ -Yb 3+ . In contrast, the rare-earth cations La 3+ and Ce 3+ are represented in each case by only a single compound namely La 4 B 4 O 11 F 2 [5] and CeB 2 O 4 F [6], respectively. In fact, a lutetium fluoride borate is unknown up to now.…”

“…For this reason, we focused our research on rare-earth fluoride borates with the cations La 3+ , Ce 3+ , and Lu 3+ . In this work, we report on the high-pressure/high-temperature synthesis of LaB 2 O 4 F, wherewith we discovered the first isotypic compound of the recently published cerium fluoride borate CeB 2 O 4 F [6]. Because of the relatively mild pressure conditions, all boron atoms of the compound LaB 2 O 4 F are coordinated by three oxygen atoms, forming trigonal-planar [BO 3 ] 3− groups, which are connected to chains.…”