A significant negative thermal expansion (NTE) in an ilmenite-type MgVO3 ceramic is reported in this paper. MgVO3 undergoes V-V dimerization at 500-550 K accompanied by a structural phase transition from the triclinic (low-temperature) to rhombohedral (high-temperature) phase. This transition induces a large anisotropic crystal structure deformation and results in a large NTE in the ceramic sample, which is caused by the microstructural effect. The NTE was observed over a temperature range of 450-630 K, and the total volume shrinkage reached approximately -0.7%. This study demonstrates that controlling the chemical bonding is a promising method for the creation of NTE materials.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)