Large lattice responses in a mixed-valence prussian blue analogue owing to electronic and spin transitions induced by X-ray irradiation

Illuminating phase changes: Absorption of X-ray photons induces reversible internal charge-transfer processes in the mixed-valence Mn/Fe cyanide Rb _0.7Mn^II_1.15[Fe^III(CN) ₆]·2 H₂O over a broad temperature range. Both continuous and abrupt phase transformations can be triggered (see scheme; HS = high spin, LS = low spin) and because the X-rays simultaneously probe the structural properties of the material, the resulting phase diagram can be elucidated in detail. (Graph presented).