  A safe, simple and easily scaleable one-step sintering method is proposed to
fabricate newly discovered superconductors of SmO1-xFxFeAs. Superconducting
transition with the onset temperature of 54.6 K and high critical fields Hc2(0)
>=200 T were confirmed in SmO1-xFxFeAs with x = 0.3. At 5 K and self field,
critical current density Jc estimated from the magnetization hysteresis using
the whole sample size and the average particle size reached 8.5x10^3 and
1.2x10^6 A/cm^2, respectively. Moreover, the Jc exhibited a very weak
dependence on magnetic field. Microstructural characterizations revealed that
the whole sample Jc improvement could be achieved by either perfect texture or
optimization of fabrication process in this strongly-layered superconductor.
Our results clearly demonstrated that one-step synthesis technique is unique
and versatile and hence can be tailored easily for other rare earth derivatives
of REFeAsO superconductors.
