Electrostatic-doping-controlled phase separation in electron-doped manganites

The coexistence of distinct insulating and metallic phases within the same manganite sample, i.e., phase separation scenario, provides an excellent platform for tailoring the complex electronic and magnetic properties of strongly correlated materials. Here, based on an electric-double-layer transistor configuration, we demonstrate the dynamic control of two entirely different phases - canted G-type antiferromagnetic metal and C-type antiferromagnetic charge/orbital ordered insulator phase - in electron-doped system Ca1-xCexMnO3 (x = 0.05). The reversible metal-to-insulator transition, enhanced colossal magnetoresistance (∼27 000% for Vg = 3.0 V), and giant memory effect have been observed, which can be attributed to an electronic phase separation scenario manipulated by a tiny doping-level-variation of less than 0.02 electrons per formula unit. In addition, the controllable multi-resistance states by the combined application of magnetic and electrostatic fields may serve as an indicator to probe the dynamic multiphase competition of strongly correlated oxides. These results offer crucial information to understand the physical nature of phase separation phenomena in manganite systems.