Premium
Clathrate XI K 58 Zn 122 Sb 207 : A New Branch on the Clathrate Family Tree
Author(s) -
Cox Tori,
Gvozdetskyi Volodymyr,
Bertolami Mark,
Lee Shan,
Shipley Kristian,
Lebedev Oleg I.,
Zaikina Julia V.
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202011120
Subject(s) - clathrate hydrate , crystal twinning , crystallography , tetragonal crystal system , powder diffraction , chemistry , bismuth , x ray crystallography , electron diffraction , crystal structure , diffraction , materials science , hydrate , physics , optics , microstructure , organic chemistry
Abstract The compositional screening of K‐Zn‐Sb ternary system aided by machine learning, rapid exploratory synthesis using KH salt‐like precursor and in situ powder X‐ray diffraction yielded a novel clathrate type XI K 58 Zn 122 Sb 207 . This clathrate consists of a 3D Zn‐Sb framework hosting K + ions inside polyhedral cages, some of which are reminiscent of known clathrate types while others are unique to this structure type. The complex non‐centrosymmetric structure in the tetragonal space group I 4 ‾ 2 m was solved by means of single crystal X‐ray diffraction as a 6‐component twin due to pseudocubic symmetry and further confirmed by high‐resolution synchrotron powder X‐ray diffraction and state‐of‐the‐art scanning transmission electron microscopy. The electron‐precise composition of this clathrate yields narrow‐gap p ‐type semiconductor with extraordinarily low thermal conductivity due to displacement or “rattling” of K cations inside oversized cages and as well as to twinning, stacking faults and antiphase boundary defects.