Single Laser Shot Photoinduced Phase Transition of Rubidium Manganese Hexacyanoferrate Investigated by X-ray Diffraction

We have studied by X-ray diffraction the phase transition of microcrystals of rubidium manganese hexacyanoferrate, for which combined electron transfer and structural reorganization are responsible for a change of magnetic properties. The Rb0.94Mn[Fe(CN)(6)](0.98)center dot 2.5H(2)O system undergoes a phase transition between the tetragonal phase Fe-II(S = 0)-CN-Mn-III(S = 2) and the cubic Fe-III(S = 1/2)-CN-Mn-II(S = 5/2) phases. The thermal equilibrium phase transition shows a broad regime of bistability, responsible for the appearance of a thermal hysteresis in the approximate 185-300 K temperature range. We used a deposited film to study by X-ray diffraction the switching from the tetragonal phase to the cubic phase, induced inside the thermal hysteresis by a single laser shot of tuneable power. Compared to previous measurements using local probes, our results show that the ns laser pulse induces a stable long-range ordered cubic phase when conversion is partial or complete.