New high-pressure polymorph of non-linear optical crystal BaTeMo2O9

Abstract

High-pressure synchrotron X-ray diffraction on the nonlinear optical crystal α-BaTeMo2O9 (α -BTM) has revealed a new polymorph of γ-BTM having a monoclinic space group of P21. This first order phase transition from the orthorhombic Pca21 to the new monoclinic P21 structure occurs at 3.8 GPa pressure. The mechanism of the phase transition under high pressure is attributed to the anisotropic pressure response along different crystallographic directions. © 2015 American Chemical Society