A novel low temperature synthesis route for SmFeAsO1−xFx bulk superconductor with improved transport properties

Abstract

Polycrystalline bulk samples of SmFeAsO1−xFx with 0 ≤x≤0.4 are synthesized at a temperature as low as 850 ◦C using a partially reacted precursor. The temperature dependence of resistivity and ac susceptibility measurements show superconducting transitions for all the fluorine doped samples and a TC of 55.3 K, is observed for the sample with x = 0.4, processed at such a lower temperature. Moreover, for the first time,a transport JC (752 A/cm2 at 12 K) is measured in optimized bulk samples (x = 0.3) synthesized at 850 ◦C and ambient pressure. The new synthesis route which drastically reduces the processing temperatures can be of great use for conductor applications in respect of fluorine doped rare earth iron oxypnictides in general and Sm1111 in particular