n- and p-type behaviour of the gold-substituted type-I clathrate, Ba8AuxSi46-x(x=5.4 and 5.9)
n- and p-type behaviour of the gold-substituted type-I clathrate, Ba8AuxSi46-x(x=5.4 and 5.9)
复制标题
DOI：
10.1016/j.crci.2004.12.004
复制
发表时间：
2005-01-01
影响因子：
1.6
通讯作者：
Pouchard, M
中科院分区：
文献类型：
--
作者：
Jaussaud, N;Gravereau, P;Pouchard, M
本文报道了两种金取代硅包合物Ba_8Si_4_6-x的合成。一种没有后续处理（所谓的AG表示生长状态），另一种在石英管中退火后（所谓的A表示退火）。对两种样品的单晶结构分析表明，AG和A样品的x Au含量分别为5.4和5.9。这两种样品的特征在于塞贝克系数和电导率测量。以及Si-29 MAS NMR光谱。AG样品是接近金属的n型半导体，而A样品表现出p型金属行为。NMR谱与Si（3s）轨道在费米能级对电导率的高贡献一致。
Two samples of the gold-substituted silicon clathrate, Ba8AuxSi46-x, have been synthesized from the elements at high temperature. one without subsequent treatment (so-called AG for as-grown) and the other after annealing in a silica tube (so-called A for annealed). A structure analysis on single crystal of both samples shows that the x Au content for the AG and A sample is 5.4 and 5.9, respectively. Both samples have been characterized by Seebeck coefficient and electrical conductivity measurements. as well as by Si-29 MAS NMR spectroscopy. The AG sample is an n-type semi conductor close to a metal, whereas the A one exhibits a p-type metallic behaviour. The NMR spectra are consistent with a high contribution to the conductivity of the Si(3s) orbitals at the Fermi level.