Area negative thermal expansion in a beryllium borate LiBeBO3 with edge sharing tetrahedra†
Abstract
A very rare area negative thermal expansion phenomenon is observed in a newly discovered alkali beryllium borate LiBeBO3, which is characterized by [BeBO3]∞ double layers intraconnected by edge-sharing BeO4 tetrahedra. This unusual thermal behavior is attributed to the combined vibrational effects of the abnormal Be–O structures and Li+ cations.