High-pressure RHEED Controlled PLD of Complex Oxides

Abstract

Format

This is a copy of the slides presented at the meeting but not formally written up for the volume.

Abstract

Recent developments in strongly correlated materials, in particularly metal oxides, have led to many inventive ideas to apply these materials in novel device concepts. During the last decade a tremendous progress has been made in controlling these complicated materials. To name a few, these are the epitaxial growth technique, understanding of the properties of their defect structure, atomic-level control of their layering, in the case of oxides the manipulation of the oxygen contents and dopant densities, etc.. With our development of high-pressure reflection high-energy electron diffraction during pulsed laser deposition we are able to control the growth of these materials at atomic level. Two independent processes, i.e., nucleation and growth, play an important role during vapour-phase epitaxial growth on an atomically flat surface. Here, nucleation causes the formation of surface steps and subsequent growth causes the lateral movement of these steps. Both processes are determined by kinetics, since they take place far from thermodynamic equilibrium, and affect the final surface morphology. The applicability of high-pressure RHEED to extract the kinetic parameters, determining the growth of complex oxides in PLD, will be demonstrated. In PLD, deposition and growth are separated in time, which enables measurement of the kinetic parameters at growth conditions by monitoring the decay of the adatom density between the deposition pulses and the influence of the kinetics on the epitaxial growth of oxides will be presented.With this controlled growth one is able to design artificial materials with specific properties by atomic-scale tailoring of their compositions. In this presentation we will focus on the epitaxial growth of such heterostructures with special emphasis on growth kinetics as well as the termination control of each deposited layer (final and starting atomic configuration).