Electronic phenomena of transition metal oxides

Abstract

Transition metal oxides with ABO3 or BO2 structures have become one of the major research fields in solid state science, as they exhibit an impressive variety of unusual and exotic phenomena with potential for their exploitation in real-world applications. The interest in these materials was especially triggered by the search for high-temperature superconductors, the demand for insulators with high dielectric constants being the backbone of modern information technology, with the discovery of the resistive switching effect underpinning the field of neuromorphic computing. All of these applications rely on the variability of the oxide’s electronic structure, which is mainly determined by the transition metal ion having the ability to adopt different valence states, depending on the chemical surroundings. Hence, the properties of the oxide can be manipulated by modifying its stoichiometry, which can be achieved by applying gradients of electric or chemical potential. As in the case of transition metal oxides, these modifications are often only confined to extended defects, and exhibit an intrinsic heterogeneity that enables the miniaturization of devices down to the nanoscale (Fragment tekstu).