Electric field control of physical properties in oxide thin films via ionic liquid gating

Abstract

This dissertation investigates electric-field control of structural, electronic, magnetic, and optical properties in oxide thin films using ionic liquid gating. By combining transport measurements, optical spectroscopy, microscopy, and structural characterization, reversible and non-volatile phase transformations driven by oxygen vacancy migration are demonstrated in several functional oxides. The work reveals controlled metal–insulator transitions, modulation of magnetic order, and tunable optical responses in epitaxial thin films and micro-structured devices. Particular emphasis is placed on the microscopic mechanisms of ionic liquid gating and their spatial control through device geometry. The results establish ionic liquid gating as a powerful tool for low-energy manipulation of material properties and provide new perspectives for oxide electronics, spintronics, and reconfigurable functional devices.