Fabrication and characterization of heterostructures of oxide insulators

Abstract

Transition metal oxides have attracted tremendous attention from many researchers due to its versatile functionalities, such as Colossal magnetoresistance(CMR), Superconductivity, Ferromagnetism, Ferroelectricity and Multiferrocity. As the growth technique is developing, artificial structure could be designed with atomic precision and expanded the horizon of possibilities. Since the discovery of 2-Dimensional electron gas at LaAlO3/SrTiO3 interface, many exotic properties are discovered but the mechanisms of superconductivity, ferromagnetism is not clear yet. In this thesis, laser beam parameter which is most delicate one has been optimized by optical simulation method and optical apparatus are installed according to the simulation. LAO films are grown on STO substrate layer by layer growth mode with RHEED monitoring. And Resistivity, Magnetic property, Hall effect, X-ray diffraction experiment had been performed. From the Hall effect and magnetic properties, it's been verified that majority carrier is originated from oxygen deficiency and proposed the interconnetion between in-plane magnetism and oxygen defect. Also we synthesis LAO/STO superlattice and analyzed with X-ray diffraction and reflectivity to verify the possibility that the artificial structure could be successfully realized