Channeling Studies of YBaCuO Thin Films with Combined RBS and PIXE

Thin films of YBa2Cu3O7−x (YBCO) deposited by hollow cathode discharge sputtering on (100) MgO, (100) SrTiO3 and (100) Zr(Y)O2 (YSZ) buffered r-plane sapphire, are studied using channeling techniques. Simultaneous Rutherford backscattering spectrometry (RBS) and particle induced X-ray emission (PIXE) are applied to investigate the high-Tc superconducting films (HTSC) and the pure substrates. Using the RBS signal of Ba near the surface, we obtain minimum yields of 3.2%, 17% and 18% for films on MgO, SrTiO3 and Zr(Y)O2 substrates respectively. The minimum yields measured on thin films with PIXE depend on the film thickness, since X-rays from the total depth of the film are integrated. For the films investigated, minimum yields in the range 12–40% are measured when BaL, YL, YKα and CuKα X-rays are detected. A constant half-angle for 〈100〉 axial scans was found for RBS and PIXE measurements on all YBCO samples when signals from Ba, Y and Cu were used. Results on the homogeneity of a large area deposition (50 × 50 mm2) are presented. The present channeling results are compared with Tc, and jc measurements.