Interplay of Static and Dynamic Correlations in Ferroelectric Metal Organic Framework, (NH4)Zn(HCO2)3

The Metal Organic Framework, (NH4)Zn(HCO2)3 exhibits a transition to a ferroelectric state at 180 K. However, the triangular lattice on which dipoles sit suggests a degree of frustration in this transition. We have observed diffuse, planar maxima on our in-house instrument, which we believe to be associated with correlated disorder, as well as structured thermal diffuse scattering. To separate and understand these two contributions to the scattering, we propose to measure diffuse scattering and inelastic X-ray scattering (DS & IXS). This study has two main aims: (i) to understand the nature of static correlated disorder as a function of temperature and (ii) elucidate the interplay between correlated disorder and lattice dynamics in the system. Results will be compared with simulations using Monte Carlo and supercell lattice dynamics.