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Owing to the effect of atomic vibrations, a high-temperature phase usually features a relatively smaller density when compared with a low-temperature phase. In this work, a new SrCdB2O5 phase has been discovered. According to the crystallization temperature from low to high, the new SrCdB2O5 phase can be regarded as the high-temperature β-SrCdB2O5 phase. The density of β-SrCdB2O5 is obviously larger than that of α-SrCdB2O5, meanwhile β-SrCdB2O5 is energetically favored. This unusual density evolution phenomenon has been investigated. In addition, the Pb(2+)-doped compounds, PbxSr1-xCdB2O5 (x = 0.125, 0.25, 0.375, 0.5), have also been investigated by powder refinement.

The magnesium borate fluoride Mg5(BO3)3F was grown by spontaneous crystallization with molten flux based on the MgF2-LiF-Na2CO3-H3BO3 solvent. Structure solution from single-crystal X-ray diffraction shows that the title compound crystallizes in the orthorhombic space group Pnma (No. 62) with cell dimensions of a = 10.068(5) Å, b = 14.858(7) Å, c = 4.540(2) Å and Z = 4. Its structure features a three-dimensional (3D) Mg-O-F framework composed of MgO5F and MgO6 polyhedra and isolated BO3 groups. The detailed structure comparison referred to Mg5(BO3)3F, Mg3BO3F3 and β-Mg2BO3F was carried out. The infrared spectrum (IR) and the bond valence sum (BVS) calculations of Mg5(BO3)3F verify the validity of the structure. The calculated band structure and the density of states of Mg5(BO3)3F suggest that its indirect bandgap is 5.27 eV. The compound was additionally investigated by UV/Vis-NIR diffuse reflectance spectroscopy and thermal analysis. [ABSTRACT FROM AUTHOR]

Colorless and transparent crystals of the new title compounds are prepared by melting mixtures of Sr(NO3)2, ZnO (CdO), PbO, and H3BO3 in a molar ratio of 1:4:12:4 (Pt crucible, 900 °C, 24 h). Both compounds crystallize in the rhombohedral space group R...c with Z = 6 (single crystal XRD). Their structures contain isolated [B18O36]18- anionic groups. The Sr:M ratio of 8:1 is discussed. [ABSTRACT FROM AUTHOR]

Small colorless crystals of the new polymorph β-Cd3B2O6 are prepared in a PbO-MoO3 flux using a mixture of CdO, H3BO3, PbO, and MoO3 in the molar ratio of 3.3:2:1:1 (Pt crucible, 700 °C). [ABSTRACT FROM AUTHOR]

Single crystals of a new polymorph of CsB5O8 are grown from a mixture of Cs2CO3, H3BO3, and MoO3 in a molar ratio of 1:4:2 (Pt crucible, 650 °C, 20 h; controlled cooling). [ABSTRACT FROM AUTHOR]