When local deformations trigger lattice instability: Flow diagram investigations for photoinduced and quenched metastable states in a Prussian blue analog

作者：Itoi Miho^*; Maurin Isabelle; Varret Francois; Frye Franz A; Talham Daniel R; Chernyshov Dmitry; Boukheddaden Kamel

来源：Physical Review B, 2013, 88(9): 094104.

DOI：10.1103/PhysRevB.88.094104

The structural aspects of the metastable states for K0.32Co[Fe(CN)(6)](0.76)center dot 3H(2)O have been investigated by synchrotron x-ray powder diffraction. The title compound exhibits nonequilibrium high spin (HS) states of Co-II(S = 3/2)-Fe-III(S = 1/2) configuration, induced by rapid cooling or photoexcitation from the low-temperature (LT) phase. By introducing a new local order parameter of tilting angle between cyanide-bridged Fe and Co-based octahedra, we discovered the existence of a precursor phenomenon triggering the collective instability during the thermal relaxation of the photoexcited (PX) state. Moreover, we introduced a methodology, based on the flow diagram studies, which allowed us to clearly distinguish the obtained metastable states through their strength of spin-lattice coupling, leading to various pathways in the phase space during the combined electroelastic relaxation process.

• 出版日期2013-9-6