Abstract
利用磁性,熱性及中子繞射,研究鉛2213系統中稀土離子如鐠及釓的磁有序及超導性質.Low temperature magnetic study for the insulating Pb-2213system. Magnetic susceptibility, heat capacity, neutrondiffraction measurements indicated an anomalous highntiferromagnetic Neel temperature TN(Pr) = 6 K with an onesetaround 11 K for Pb2Sr2PrCu3O8 as compared to TN(Gd) = 2.2 K forPb2Sr2GdCu3O8. Detailed neutron diffraction data shows complexmagnetic behavior around TN(Pr), and the coherence length alongc axis is 20 angstron indiciated that the antiferromagneticordering was non-perfect 3D ordering. The new Pb2Ba2RCu3O8 (R =Pr and Gd) compounds were synthesized. In this 2213 system, theBa substitution for Sr dramatically induced the Pr orderingtemperature TN(Pr), may caused by decreased the Pr-O bondlength, just as the same feature of Tl(BaSr)2PrCu2O7.