Imaging electronic phase separation in a complex ferrite

Complex transition metal oxides undergo many structural, electronic, and magnetic transitions, sometimes leading to phase separation e.g. in perovskite manganites. We propose to investigate the unexplored microstructure of electronic phase segregation in CaFe3O5. Below a magnetic transition at ~300 K, this separates into charge ordered (CO) and charge averaged (CA) phases. The high temperature and two low temperature phases all have the same Cmcm unit cell, and in XRD are distinguishable just by small differences in their cell parameters and derived strains. A 3DXRD grain mapping experiment on a ceramic pellet from 80 to 400 K is proposed. This will explore microstructural changes at the transition such as relations between domains and cell axis directions of the CO and CA phases, and how their lattice strains vary across the ceramic sample. The hard X-rays and high resolution of ID11 will be needed to distinguish the very similar cell parameters of the low T CO and CA phases.