title: High-pressure synthesis and superconductivity of the Laves phase compound Ca(Al,Si)2 composed of truncated tetrahedral cages Ca@(Al,Si))12.
abstract: The Zintl compound CaAl2Si2 peritectically decomposes to a new ternary cubic Laves phase Ca(Al,Si)2 and an Al-Si eutectic at temperatures above 750 °C under a pressure of 13 GPa. The ternary Laves phase compound can also be prepared as solid solutions Ca(Al(1-x)Si(x))2 (0.35 ≤ x ≤ 0.75) directly from the ternary mixtures under high-pressure and high-temperature conditions. The cubic Laves phase structure can be regarded as a type of clathrate compound composed of face-sharing truncated tetrahedral cages with Ca atoms at the center, Ca@(Al,Si)12. The compound with a stoichiometric composition CaAlSi exhibits superconductivity with a transition temperature of 2.6 K. This is the first superconducting Laves phase compound composed solely of commonly found elements.
authors: Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
authors: Masashi
authors: M
authors: Tanaka
authors: Shuai
authors: S
authors: Zhang
authors: Kei
authors: K
authors: Inumaru
authors: Shoji
authors: S
authors: Yamanaka