Christina Ambrus

Order and disorder in a Mn-based Prussian Blue analogue: synchrotron diffraction and magnetic susceptibility study

Themetal-substituted analogues of Prussian Blue have attracted renewed interest due to their unique combination of magnetic and optical properties. Current research in this field is aimed at designing transparent and optically tunable magnetic materials. A fundamental problem for such design is the presence of intrinsic structural disorder M(CN)6 vacancies filled by (H2O)6 clusters which strongly affects magnetic and optical properties. We characterize the Mn[Mn(CN)6]2/ 3c(6H2O)1/3 analogue with synchrotron diffraction, neutron magnetic scattering and magnetization measurements. Synchrotron diffraction from a single crystal revealed a pronounced diffuse signal linked to a correlated distribution of [Mn(CN)6] vacancies filled by (H2O)6 water clusters. A complex frequency dependence of the real and imaginary parts of the magnetic susceptibility near Tc, somewhat similar to that of a cluster-glass, indicates a correlated disorder of magnetic centres.