Pressure-induced structural transformations in In2-xYx(MoO4)3 systems

In this work, we report results of high-pressure Raman experiments (P<8GPa) on In2-xYxMo3O12 for x=0.0 and 0.5. A crystalline to crystalline structural phase transition and pressure-induced amorphization (PIA) have been identified. The structural phase transition takes place at 1.5 and 1.0GPa for In-2(MoO4)(3) and In1.5Y0.5(MoO4)(3), respectively, resulting in the change of structure from monoclinic P2(1)/a to a more denser structure. The PIA started at 5 and 3.4GPa for In2Mo3O12 and In1.5Y0.5Mo3O12, respectively. The amorphization process takes place in two stages in the case of In1.5Y0.5Mo3O12 phase, while for In2Mo3O12, it is not complete until the pressure is as high as 7GPa. Our results also suggest that with increase of ionic size of the A(3+) ions, the octahedral distortion increases and consequently larger local structural disorder is introduced in the A(2)(MoO4)(3) system, where A is a trivalent ion (In, Y3+, Sc3+, Fe3+, etc.). Copyright (c) 2015 John Wiley & Sons, Ltd.