Ultralow Lattice Thermal Conductivity in Ba23M10Ge10Sb25‑δ (M = Ga, In): Quaternary Compounds Containing Ba-Centered Dodecahedra

Two new quaternary compounds, Ba23Ga10Ge10Sb25 and Ba23In10Ge10Sb24.79, have been synthesized by using the high temperature solid-state reactions. These new phases exhibit huge unit cells (V = 17 514.6 and 18 455.8 Å3 for Ga- and In-containing compounds, respectively),which comprise 544 atoms and fe...

Full description

Saved in:
Bibliographic Details
Published in:Chemistry of materials 2018-07, Vol.30 (14), p.4713-4719
Main Authors: Pan, Ming-Yan, Qi, Hong-Ji, Liu, Xiao-Cun, Bai, Ming-Cheng, Xia, Sheng-Qing
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Two new quaternary compounds, Ba23Ga10Ge10Sb25 and Ba23In10Ge10Sb24.79, have been synthesized by using the high temperature solid-state reactions. These new phases exhibit huge unit cells (V = 17 514.6 and 18 455.8 Å3 for Ga- and In-containing compounds, respectively),which comprise 544 atoms and feature “onion-like” M20Ge20Sb30 clusters connected through the Sb–Sb bonds. Among these clusters, substantial isolated units such as Ba, Sb, or Sb3 trimers are filled. With such a complex structure as well as the large unit cell and substantial heavy constituent atoms, ultralow lattice thermal conductivity (κl) was observed for Ba23Ga10Ge10Sb25, ranging from 0.2 to 0.38 W·m–1·K–1 from 323 to 823 K. As a result, a maximun ZT of 0.27 was achieved at 823 K.
ISSN:0897-4756
1520-5002
DOI:10.1021/acs.chemmater.8b01441