Phase transitions in Mn(Mo1-xWx)O4 oxides under the effect of high pressure and temperature

ABO(4) compounds exhibit various phase transitions identified in the literature. The phase transitions between monoclinic -C-2/m and wolframite P-2/c structures of Mn(Mo1-xWx)O-4 compounds, which can be induced by pressure or temperature, are studied on the basis of X-ray diffraction analyses. The large optical contrast associated with both these structures and Mo/W environments can be exploited to propose efficient piezochromic sensors (thanks to the monoclinic to wolframite transition vs. pressure) and thermal sensors (thanks to the reverse transformation), the thermochromic temperature being able to be tuned via the Mo/W ratio. A(Mo,W)O-4 phase diagram: from wolframite to monoclinic compounds (drawn from the updated Bastide's diagram from Errandonea and Manjo ). (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim