Photoinduced phase transitions over three phases in Ba0.9 Sr0.1 V13 O18

Ba0.9Sr0.1V13O18 exhibits two ordered phases caused by the charge/orbital ordering of the d electrons on the V ions. We have succeeded in observing photoinduced phase transitions over three phases in this compound: a transition from the low-temperature phase to the high-temperature phase within 0.3 ps, followed by a transition to the intermediate-temperature phase within 2 ps. The relationship between the symmetry at each of the three phases plays a key role in the dynamics of the photoinduced phase transitions in such a compound.