Discrimination between gate-induced electrostatic and electrochemical characteristics in insulator-to-metal transition of manganite thin films

We propose a method of discriminating whether the gating effect is electrostatic or electrochemical on an electric double-layer transistor (EDLT), which can be a good guideline for examining the nature of EDLTs. The electrochemical effect between a channel and an ionic liquid depends on the gate voltage (V_G). Our study on the dependence of the transport properties of a (La_0.525Pr_0.1Ca_0.375)MnO₃ (LPCMO) EDLT on V_G revealed that the electrostatic effect is dominant below |V_G| = 2 V, whereas the electrochemical effect is dominant at higher voltages. The modulation of the insulator-to-metal transition property of LPCMO was realized through the electrostatic effect.