New oxypnictide superconductors: PrOFe1-xCoxAs

作者：Prakash J; Singh S J; Das D; Patnaik S^*; Ganguli A K

来源：Journal of Solid State Chemistry, 2010, 183(2): 338-343.

DOI：10.1016/j.jssc.2009.11.026

• Oxypnictide superconductors
• Mossbauer effect
• Hall effect

Oxypnictides of the type PrOFe1-xCoxAs (x <= 0.3) were synthesized for the first time by the sealed tube method. All the compounds were found to be monophasic and crystallize in the tetragonal ZrCuSiAs type structure (space group=P4/nmm) and the lattice parameters (a and c) decrease with increase in cobalt content. Mossbauer measurements of the compounds indicate low spin Fe2+ in tetrahedral coordination. Resistivity and magnetization studies reveal superconducting transitions in compounds with 'x'=0.05, 0.10 and 0.15, with maximum transition temperature (T-c) at similar to 14K in the compound with 'x'=0.1. The variation of resistivity with temperature under different magnetic field has been studied to estimate the upper critical field (H-c2) (similar to 50.2T for the 'x'=0.1 composition). The Seebeck and Hall coefficient (R-H) Suggests electron type charge carriers in these compound and the charge carrier density increases with increase in Co-doping.

• 出版日期2010-2