Substitutional tuning of electronic phase separation in CaFe3O5

Abstract

Electronic phase separation into charge-ordered (CO) and charge-averaged (CA) phases in Ca⁢Fe3−𝑥⁢𝑀𝑥⁢O5 samples for dopants 𝑀=Mn and Co has been investigated using powder neutron and x-ray diffraction, magnetization, and Mössbauer spectroscopy measurements. Electronic phase separation is observed in lightly doped Ca⁢Fe3⁢O5 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 300–320K providing strong evidence for a lattice strain-driven mechanism that couples their magnetic transitions.