Substitutional tuning of electronic phase separation in CaFe3O5

Electronic phase separation into charge-ordered (CO) and charge-averaged (CA) phases in $\mathrm{Ca}{\mathrm{Fe}}_{3\ensuremath{-}x}{M}_x{\mathrm{O}}₅$ samples for dopants $M=\mathrm{Mn}$ and Co has been investigated using powder neutron and x-ray diffraction, magnetization, and M\"ossbauer spectroscopy measurements. Electronic phase separation is observed in lightly doped $\mathrm{Ca}{\mathrm{Fe}}₃{\mathrm{O}}₅$ samples, where $4--10%$ Ca is replaced by Mn, Fe, or Co, and the CA ground state is stabilized at higher doping levels. The CO and CA phases are found to emerge below a common magnetic ordering temperature at $300--320\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ providing strong evidence for a lattice strain-driven mechanism that couples their magnetic transitions.