Superconductivity in Li-doped α-rhombohedral boron
Superconductivity in Li-doped α-rhombohedral boron
复制标题
DOI：
10.1103/physrevb.83.184507
复制
发表时间：
2011-05-16
影响因子：
3.7
通讯作者：
Kimura, K.
中科院分区：
文献类型：
--
作者：
Nagatochi, T.;Hyodo, H.;Kimura, K.
在掺锂的α-菱面体硼（α-B-12）中观察到了金属相变和超导电性。作者建立了一种提纯方法，获得了大量高纯度的α-B-12粉末。在Mo或Ta管中通过气相扩散处理（VDP）尝试将Li掺杂到纯化的α-B-12中。掺锂的α-B-12含有金属闪光颗粒。在具有标称组成LixB 12（x = 1.0、1.4、1.5、1.7或2.5）的这种化合物中观察到迈斯纳效应（T-c = 3.2-7 K）。至于Li2.5B12，其电导率的温度依赖性指示金属特性，并且在迈斯纳温度附近检测到其电阻率下降。用透射电子显微镜-电子能量损失谱（TEM EELS）研究了掺锂α-B-12晶体中Li边和费米边的存在。还观察到晶格膨胀，这是金属掺杂到晶体中的众所周知的指标。因此，成功地实现了Li掺杂到α-B-12中。我们的工作还表明，有可能将更大量的Li掺杂到α-B-12中并提高其T-c。
Metal transition and superconductivity were observed in Li-doped alpha-rhombohedral boron (alpha-B-12). The authors have established a purification method and obtained a large amount of high-purity alpha-B-12 powder. Li doping into purified alpha-B-12 was attempted by vapor diffusion processing (VDP) in a Mo or Ta tube. Li-doped alpha-B-12 contained metallic glittering particles. Meissner effects were observed in such a compound with the nominal composition LixB12 (x = 1.0, 1.4, 1.5, 1.7, or 2.5) (T-c = 3.2-7 K). As for Li2.5B12, the temperature dependence of its electrical conductivity indicates a metallic character and its electrical resistivity drop is detected near the Meissner temperature. The existence of Li and Fermi edges in Li-doped alpha-B-12 crystals was verified by transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS). Lattice expansion, which is a well-known indicator of metal doping into a crystal, was also observed. Thus, Li doping into alpha-B-12 was successfully achieved. Our work also suggests that it is possible to dope a larger amount of Li into alpha-B-12 and to increase its T-c.