PREPARATION, STRUCTURAL AND MAGNETIC-PROPERTIES OF ELECTRON-DOPED INFINITE-LAYER HTSC SR1-XNDXCUO2-DELTA

We present our method of fabricating superconducting compounds of the infinite-layer structure Sr1-xNdxCuO2-delta with various doping concentrations. The samples undergo a high temperature high pressure process and are then bulk superconductors without any further treatment. A slightly reducing atmosphere was necessary to get doped layer-phases. Refinement of the crystallographic data was done by a least squares method. The T(c)onset values are in the range of 36-41 K. The lower critical field H(c1)ab(T=0) is extrapolated to 15 G, while magnetization cycles show extremely weak pinning behaviour. From photoemission data a considerably diminished Cu-O-hybridisation is found. The particular shape of partial Nd-valence band spectra for these compounds shows Nd to work as a trivalent dopant for divalent Sr.