Observation of near-zero thermal expansion in CrVMoO7

Abstract

Materials with zero thermal expansion (ZTE) are important for many high-performance applications but are very rare. Here we report the discovery and characterization of near-ZTE in CrVMoO7. CrVMoO7 shows near-ZTE in a wide range of working temperatures (av ∼ -1.92 × 10−6 K−1, 100–240 K and 2.28 × 10−6 K−1, 240–473 K). This material shows small thermal expansion along two axes, with negative thermal expansion along the third axis that nearly cancels the small positive expansion along the other two axes. Through the joint characterizations, the transverse vibrations of O6 and O4 atoms contribute more to the NTE. In this work, CrVMoO7 provides a new option in the ZTE field as an undoped single-phase material.