  X-ray diffraction and Raman scattering studies on scheelite structured barium
molybdate show that, at 5.8 GPa, it undergoes a first order phase transition to
fergusonite structure (I2/a, Z=4), asobserved in iso-structural barium
tungstate.At still higher pressures, barium molybdate transform to another
phase between 7.2-9.5 GPa. On release of pressure from 15.8 GPa, the initial
phase is recovered implying that the observed structural modifications are
reversible.
