Abstract Single phase TmB12, YbB12 and LuB12 were successfully obtained by the arc-melting and floating zone methods. The XPS measurements of these compounds have indicated that (1) only YbB12 is a valence fluctuating compound with the valency of +2.9 at room temperature, (2) the correlation energy between Yb2+ and Yb3+ ions is about 6.0 eV, (3) Tm and Lu ions in the dodecaborides are in a trivalent state
An exceptionally-high diffraction quality dodecaboride LUB12: Growth and single-crystal structure
作者:Alexander P. Dudka、Olga N. Khrykina、Nadezhda B. Bolotina、Natalya Yu. Shitsevalova、Volodymyr B. Filipov、Nikolay E. Sluchanko
DOI:10.1016/j.jallcom.2016.09.059
日期:2017.1
X-ray structure analysis are grown by the modified crucibleless inductive floating zone melting. A thoroughly treated single crystal is used to collect a high-resolution data set up to sinθ/λ = 1.36 Å at 293 K, which has been reduced to 271 symmetry-independent reflections. Residual factors of the structure refinement in the symmetry group are 1(||)/w2(||) = 0.20/0.14% in a 13-parametric structure model
通过精确的 X 射线结构分析证实,LuB 单晶具有极高的衍射质量,是通过改进的无坩埚感应浮动区熔炼来生长的。经过彻底处理的单晶用于收集在 293 K 时达到 sinθ/λ = 1.36 Å 的高分辨率数据集,该数据已减少到 271 个与对称性无关的反射。在 13 参数结构模型中,对称群中结构细化的剩余因子为 1(||)/w2(||) = 0.20/0.14%。使用非谐波位移参数描述了 Lu 原子平均位置附近电子密度分布的不对称性。
Negative thermal expansion and anomalies of heat capacity of LuB<sub>50</sub> at low temperatures
作者:V. V. Novikov、N. A. Zhemoedov、A. V. Matovnikov、N. V. Mitroshenkov、S. V. Kuznetsov、S. L. Bud'ko
DOI:10.1039/c5dt01406a
日期:——
Heat capacity and thermalexpansion of LuB50 boride were experimentally studied in the 2–300 K temperature range. The data reveal an anomalous contribution to the heat capacity at lowtemperatures. The value of this contribution is proportional to the first degree of temperature. It was identified that this anomaly in heat capacity is caused by the effect of disorder in the LuB50 crystalline structure