Near‐Zero Thermal Expansion and High Ultraviolet Transparency in a Borate Crystal of Zn₄B₆O₁₃

Abstract

Intrinsic isotropic near-zero thermal expansion is discovered in borate crystal Zn₄ B₆ O₁₃ with high transparency in the ultraviolet region. First-principles calculations demonstrate that the very low thermal expansion originates mainly from the invariability of the solid [B₂₄ O₄₈ ] truncated octahedra that are fixed by the [Zn₄ O₁₃ ] clusters in the ZBO structure.