Origin of the DOS pseudogap and Hume-Rothery stabilization mechanism in RT-type Al48Mg64Zn48 and Al84Li52Cu24 1/1-1/1-1/1 approximants
Origin of the DOS pseudogap and Hume-Rothery stabilization mechanism in RT-type Al48Mg64Zn48 and Al84Li52Cu24 1/1-1/1-1/1 approximants
复制标题
RT 型 Al48Mg64Zn48 和 Al84Li52Cu24 1/1-1/1-1/1 近似中 DOS 赝能隙和 Hume-Rothery 稳定机制的起源
DOI：
10.1080/14786435.2011.604357
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发表时间：
2011
影响因子：
1.6
通讯作者：
H.Sato and U.Mizutani
中科院分区：
文献类型：
--
作者：
M.Inukai;E.S.Zijlstra;H.Sato and U.Mizutani
对每晶胞包含 160 个原子的两种 RT 型 Al48Mg64Zn48 和 Al84Li52Cu241/1-1/1-1/1 近似体进行了全势线性化平面波 (FLAPW) 能带计算以及随后的 FLAPW-傅立叶分析。 FLAPW-傅立叶分析表明，涉及两组以上晶格平面的费米表面-布里渊区 (FsBz) 相互作用是导致两种化合物在费米能级上形成赝能隙的原因。推断在费米能级上干扰电子的最关键晶格面组为{543} + {710} + {550}，其中 = 50，后者为{631}， = 46。费米直径的平方分别确定为 49.9±0.1 和 47.1±0.4，单位为 ，其中晶格常数。因此，匹配条件在两种化合物中均成立。研究还表明，虽然 Al48Mg64Zn48 近似中的浅赝能隙只能归因于 FsBz 相互作用，但 Al84Li52Cu24 近似中更深的赝能隙被解释为 FsBz 相互作用的叠加以及 Cu-4p 和 Al-3p 轨道之间强方向键合态的形成。
Full-potential linearized plane wave (FLAPW) band calculations with subsequent FLAPW-Fourier analyses have been performed for two RT-type Al48Mg64Zn48and Al84Li52Cu241/1-1/1-1/1 approximants containing 160 atoms per unit cell. The FLAPW-Fourier analysis revealed that the Fermi surface–Brillouin zone (FsBz) interactions involving more than two sets of lattice planes are responsible for the formation of a pseudogap across the Fermi level in both compounds. The mostcriticalsets of lattice planes interfering with electrons at the Fermi level are deduced to be {543} + {710} + {550} with = 50 in the former and {631} with = 46 in the latter. The square of the Fermi diameter is determined to be 49.9 ± 0.1 and 47.1 ± 0.4 in units of , respectively, whereais the lattice constant. Hence, the matching condition holds well in both compounds. It is also shown that, while a shallow pseudogap in the Al48Mg64Zn48approximant can be ascribed solely to the FsBz interactions, a much deeper one in the Al84Li52Cu24approximant is explained as a superposition of the FsBz interactions and the formation of strongly directional bonding states between Cu-4p and Al-3p orbitals.