  Iron-based oxypnictides substituted with yttrium have been prepared via a
conventional solid state reaction. The product after first 50 hours of reaction
showed diamagnetic-like transition at around 10 K but was not superconducting,
while additional 72 hours of high temperature heat treatment was required to
yield superconducting sample which was doped with fluoride. Temperature
dependence of the susceptibility shows both screening and Meissner effect at
around 10 K, while resistance as a function of temperature displayed a drop at
around the same temperature.
