Eu₂(MoO₄)₃ single crystal at high pressure: Structural phase transitions and amorphization probed by fluorescence spectroscopy

International audiencePressure-induced phase transitions in Eu2(MoO4)3 single crystals were studied by fluorescence spectroscopy in the range of ambient pressure to 10 GPa. The spectral range investigated was limited to the 5D0→7FJ, J=0,1,2, transitions. First, low temperature data at ambient pressure were collected for assigning spectra. The spectral changes observed with pressure increase were interpreted in terms of consecutive structural transitions, and possible space groups for the corresponding phases are proposed. A comparison between x-ray diffraction and optical spectroscopic data serves to indicate that amorphization in Eu2(MoO4)3 begins by a disordering of the oxygen sublattice