Surface Structure Analysis & Sensitivity to Atomic Layer-by-layer Engineering in Oxide Thin Films

Abstract

Format

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

Abstract

We report results of angle resolved time-of-flight ion scattering and Mass Spectroscopy of Recoil Ions (MSRI) data in charge density wave BaBiO3 and high temperature superconducting (HTS) cuprate thin films grown by Molecular Beam Epitaxy.The BaBiO3 spectra show that the film has a pure BiO termination layer. The time-of-flight data at 270 total scattering angle display dramatic changes when the azimuth angle is changed by as little as one degree. These data reveal an atomically smooth film surface and, in conjunction with computer simulations, should allow us to determine the crystal structure of the surface layers. We also show that the angle resolved MSRI spectra correlate with the quantitative results obtained from Direct Recoil Spectroscopy (DRS), enabling one to use it for accurate surface crystallography.Real time in-situ analysis of HTS thin film growth is performed for La_2-xSr_xCuO_4 and Bi_2Sr_2CaCu_2O_6+delta. The spectra show sensitivity to deposition of fractions of atomic monolayers. Results of the analysis of angular resolved time-of-flight DRS and MSRI spectra performed in order to quantitatively determine the surface composition and structure at every stage of the film growth are discussed.