Long range electronic phase separation in CaFe₃O₅.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• Phase separation in manganite perovskites is linked to colossal magnetoresistance.
• The possibility of spontaneous electronic phase separation, distinct from the high-temperature state, remains an open question.

Purpose of the Study:

• To investigate spontaneous electronic phase separation in paramagnetic CaFe3O5.
• To understand the nature of the coexisting electronic and spin ordered phases.

Main Methods:

• Experimental investigation of CaFe3O5 below its magnetic transition temperature.
• Analysis of electronic and spin ordering in the separated phases.

Main Results:

• CaFe3O5 separates into two phases with distinct electronic and spin orders below 302 K.
• One phase exhibits charge, orbital, and trimeron ordering, analogous to magnetite (Fe3O4).
• The other phase shows averaged Fe2+/Fe3+ charges, with lattice symmetry remaining unchanged.

Conclusions:

• Electronic phase separation can occur spontaneously in materials like CaFe3O5.
• Differing lattice strains from electronic orders likely drive this separation.
• Complex oxides with charge redistribution capabilities are promising for generating and controlling electronic phase-separated nanostructures.