ABSTRACT
Although zero thermal expansion (ZTE) materials have broad application prospects for high precision engineering, they are rare. Here, a new ZTE material, Ta2Mo2O11 (αl = 0.37 × 10-6 K-1, 200-600 K), is reported. A joint study of high-resolution synchrotron X-ray diffraction, temperature- and pressure-dependent Raman spectroscopy, and first-principles calculations was performed to investigate the structure and dynamics of Ta2Mo2O11 with the aim of understanding its ZTE mechanism. Ta2Mo2O11 displays a layered structure, stacking along the [001] direction. Analysis of the phonon modes indicates that positive and negative contributions to thermal expansion are balanced, and a shrinkage occurs along the layers, while the interlayer distance expands with increasing temperature, thus giving rise to the ZTE behavior of Ta2Mo2O11. The present study provides a promising ZTE material and new insights into the mechanisms of thermal expansion.
