An exceptionally-high diffraction quality dodecaboride LUB12: Growth and single-crystal structure

High-Pressure Synthesis of Light Lanthanide Dodecaborides (PrB12 and CeB12): Effects of Valence Fluctuation on Volume and Formation Pressure

“…This axis length is slightly longer (0.5–0.7%) than those of SmB 12 ( a = 7.54 Å) and GdB 12 ( a = 7.52 Å), which seems appropriate in terms of ionic radii. Figure a also shows that the a -axis of PrB 12 is consistent with those of other heavy lanthanide RB 12 compounds from TbB 12 to LuB 12 . ,− Note that the trivalent cationic radii with a coordination number of nine from ref in Figure serve as a guide for the lanthanide contraction, although the actual coordination number of the RB 12 structure is 24.…”

The lower symmetry electron-density distribution and the charge transport anisotropy in cubic dodecaboride LuB12

“…Cubic symmetry of LuB 12 is thus disputable. In spite of this, the single-crystal structure of LuB 12 has been refined not long ago in the Fm m symmetry group with exceptionally low value of residual factor R = 0.2% [16]. This contradiction has been naturally resolved using original approach developed in this study.…”

Crystal structures of dodecaborides: complexity in simplicity

“…Active studies of the RB 12 structure at various temperatures, which were started in the early 2000s but not continued at that time, were resumed later after the tetragonal distortion of the LuB 12 structure had been confirmed in the temperature range 50-75 K [48]. The structure of a LuB 12 single crystal was then thoroughly studied at room temperature [49]. The single crystals of LuB 12 were grown by modified crucibleless inductive floating zone melting using high-purity source materials: lutetium oxide Lu 2 O 3 and boron [17].…”

“…This result agrees with the result obtained in the same work [27] In the next work [33], the crystal structure of LuB 12 was studied at the four temperatures 293, 135, 95 and 50 K. To eliminate possible dependence of the results on systematic instrumental errors and on the features of the crystalline sample, the x-ray experiments were performed on three different-type diffractometers and on two LuB 12 crystals. To analyze the electron-density distribution in the crystal at room temperature, the same data were used that were previously collected on a CAD4 diffractometer (Enraf Nonius) for a precise analysis of the cubic structure of LuB 12 [49]. The x-ray data at 135 and 95 K were collected on an Xcalibur EOS S2 diffractometer with a two-dimensional CCD detector.…”