Texture Investigations on High Temperature Superconductors

The formation of a structure with strong crystallographic texture is an important requirement for highcritical current densities at 77 K in high temperature superconductive materials (HTSC). In this workseveral methods for texture investigation in the superconductive phase of BiPbSrCaCuO/Ag- andYBaCuO/AgPd-composite conductors prepared according to the “powder in tube”-method as well asin YBaCuO-thick layers are presented. For the characterisation of the texture development in dependenceon technological steps at the preparation of HTSC-composite conductors the determination of the halfwidthFWHM from the psi-scan or for one-phase specimens the determination of the Lotgering-factoris appropriate, if only a c-axis exists. The measurement of pole figures is necessary to determine, whethera rotation symmetry occurs or an orientation of the (a,b)-directions exists. The use of the omega-scanto determine the half-width is not useful, if the goniometer unit is intended and optimised for phaseanalysis and therefore the secondary monochromator cannot be relinquished.