Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI, 53706, USA.
Angew Chem Int Ed Engl. 2017 Aug 14;56(34):10145-10150. doi: 10.1002/anie.201702156. Epub 2017 Jun 21.
We illustrate how the crystal structure of Fe Pd Al provides an example of an electron-hole matching approach to inducing frustration in intermetallic systems. Its structure contains a framework based on IrAl , a binary compound that closely adheres to the 18-n rule. Upon substituting the Ir with a mixture of Fe and Pd, a competition arises between maintaining the overall ideal electron concentration and accommodating the different structural preferences of the two elements. A 2×2×2 supercell results, with Pd- and Fe-rich regions emerging. Just as in the original IrAl phase, the electronic structure of Fe Pd Al exhibits a pseudogap at the Fermi energy arising from an 18-n bonding scheme. The electron-hole matching approach's ability to combine structural complexity with electronic pseudogaps offers an avenue to new phonon glass-electron crystal materials.
我们展示了 FePdAl 的晶体结构如何为在金属间化合物系统中引入受挫提供了一个电子-空穴匹配方法的例子。它的结构包含一个基于 IrAl 的框架，IrAl 是一种紧密遵循 18-n 规则的二元化合物。在将 Ir 用 Fe 和 Pd 的混合物取代后，维持整体理想电子浓度和适应两种元素不同结构偏好之间就产生了竞争。结果得到一个 2×2×2 的超晶格，出现了 Pd 和 Fe 富区。就像在原始 IrAl 相中一样，FePdAl 的电子结构在费米能级处表现出一个赝能隙，这是由 18-n 成键方案引起的。电子-空穴匹配方法能够将结构复杂性与电子赝能隙结合起来，为新的声子玻璃-电子晶体材料提供了一种途径。
