Electrochemical formation of Yb–Ni alloy films by Li codeposition method in a molten LiCl–KCl–YbCl3 system
摘要:
Electrochemical formation of Yb-Ni alloy films at a Ni cathode was investigated in a molten LiCl-KCl-YbCl3 (0.5 mol%) at 723 K. A very thin YbNi2 film ( similar to 100 nm) was formed by potentiostatic electrolysis at 0.10 V (vs. Li+/Li) for 24 h. A much thicker YbNi2 alloy film ( similar to 7 mum) was formed by Li codeposition method (cathodic galvanostatic electrolysis at 50 mA cm(-2)) for 1 h. The formed YbNi2 films were changed to Yb2Ni17 and alpha-Ni phases by anodic potentiostatic electrolysis depending on the applied potentials. The formation potentials of Yb2Ni17 and YbNi2 were found to be 0.75 and 0.25 V, respectively. (C) 2003 Elsevier Science Ltd. All rights reserved.
Measurements of the magnetization and specific heat of YbNi2 binary alloy are reported. The DC magnetic susceptibility displays a ferromagnetic behavior with a Curie temperature T-C = 10.5 K, one of the highest found in Yb compounds. Moreover, the temperature dependence of the specific heat exhibits a lambda anomaly with a peak of 5.12 J/mol K at 9.4K. The analysis also shows an additional magnetic contribution around 32 K stemming from the crystalline electric field of a quartet at Delta(1) = 72 K and a doublet at Delta(2) = 126 K, according to the splitting of the Yb3+ ion in cubic symmetry. From the magnetic contribution to the specific heat, a relatively high Kondo temperature T-K = 27 K is estimated. Below the magnetic transition, the specific heat shows a huge value of the electronic coefficient gamma(LT) = 573 mJ/mol K, which is a signature of a heavy fermion behavior. Therefore, this alloy is a fine example of enhanced ferromagnetism and heavy fermion behavior among Yb compounds. (C) 2012 Elsevier Ltd. All rights reserved.
Electrochemical formation of Yb–Ni alloy films by Li codeposition method in a molten LiCl–KCl–YbCl3 system
作者:Takahisa Iida、Toshiyuki Nohira、Yasuhiko Ito
DOI:10.1016/s0013-4686(03)00031-8
日期:2003.5
Electrochemical formation of Yb-Ni alloy films at a Ni cathode was investigated in a molten LiCl-KCl-YbCl3 (0.5 mol%) at 723 K. A very thin YbNi2 film ( similar to 100 nm) was formed by potentiostatic electrolysis at 0.10 V (vs. Li+/Li) for 24 h. A much thicker YbNi2 alloy film ( similar to 7 mum) was formed by Li codeposition method (cathodic galvanostatic electrolysis at 50 mA cm(-2)) for 1 h. The formed YbNi2 films were changed to Yb2Ni17 and alpha-Ni phases by anodic potentiostatic electrolysis depending on the applied potentials. The formation potentials of Yb2Ni17 and YbNi2 were found to be 0.75 and 0.25 V, respectively. (C) 2003 Elsevier Science Ltd. All rights reserved.
Yb@C<sub>2<i>n</i></sub> (<i>n</i> = 40, 41, 42): New Fullerene Allotropes with Unexplored Electrochemical Properties
potentials, which have raised the assumption that such species are large-bandgap molecules. This study revealed that all isomers of Yb@C(2n) (n = 40, 41, 42) display one or two reversible oxidation steps together with four reversible reduction processes in 1,2-dichlorobenzene, even at a low scan rate (20 mV/s), which enables estimation of their electrochemical bandgaps (DeltaE = (ox)E(1)-(red)E(1)). The
合成并分离了一系列富含 (13) C 的单镱内嵌金属富勒烯 (EMF)-Yb@C(2n)(n = 40、41、42)。首次使用计算和实验 (13) C NMR 研究系统地确定了它们的笼状结构。结果表明,所有异构体均采用符合孤立五边形规则的笼状结构。详细地说,Yb@C(80) 具有 C(2v)(3) 笼;Yb@C(82)(I, II, III)分别带有C(s)(6)、C(2)(5)和C(2v)(9)笼;和 Yb@C(84)(II, III, IV) 分别具有 C(2)(13)、C(1)(12) 和 C(2)(11) 笼结构。这是描述 C(2)(13)-C(84) 和 C(1)(12)-C(84) 笼结构的第一份报告。值得注意的是,单电动势的笼状结构通常不同于相应的空富勒烯或相关的包含多个金属原子的电动势,表明富勒烯笼内的金属原子在决定 EMF 结构中起着重要作用。基于Yb@C(2)(13)-