Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Solid State Nucl Magn Reson. 2012 Feb;41:28-31. doi: 10.1016/j.ssnmr.2011.11.003. Epub 2011 Nov 22.
The atomic and electronic structures of LnAl(2) (Ln=Y, La and Lu) on Al sites were characterized by (27)Al solid state NMR spectroscopy. (27)Al isotropic metallic shifts have been determined in these cubic laves phases under both static and magic angle spinning (MAS) conditions. Based on band structure calculations, we found a strong correlation of (27)Al isotropic metallic shifts and s character of the density of states at the Fermi level on Al sites. We also found tetrahedral distortion of Al centered clusters, which can be well characterized by quadruple coupling constants and Knight shift anisotropy.
采用（27）Al 固态 NMR 光谱法对 Al 位的 LnAl（2）（Ln=Y、La 和 Lu）的原子和电子结构进行了表征。在这些立方拉维斯相中，在静态和魔角旋转（MAS）条件下均确定了（27）Al 各向同性金属位移。基于能带结构计算，我们发现 Al 位的（27）Al 各向同性金属位移与费米能级处的态密度的 s 特征之间存在很强的相关性。我们还发现了以 Al 为中心的团簇的四面体畸变，可以很好地用四重耦合常数和奈特位移各向异性来描述。
