Micro-PIXE and channeling PIXE analysis of Ag-doped YBa2Cu3O7-δ thin films

Abstract

Nuclear Microscopy, utilizing a 2 MeV He+ beam for channeling Rutherford Backscattering (RBS) and PIXE analysis, was used to characterise Ag-doped YBa2Cu3O7-δ thin films and measure the lateral distribution of the Ag. The samples were prepared by in situ two-beam pulsed laser deposition in order to investigate the effects of such dopings on critical current densities. Films deposited at temperatures above 650°C form needle-like surface structures with a length of up to 100 μm; these tend to align with in-plane a-b axis. Results for a sample prepared at a substrate temperature of 730°C and a maximum Ag concentration of 5 at.% are discussed. The needle-like structures were found to be rich in Ag and Cu, and the YBa2Cu3O7-δ film contained 0.02 at.% Ag. Broad beam PIXE-channeling results indicate that 19% of the Ag is substitutional.