5. Pb系銅酸化物超伝導体の結晶化学

抄録

The crystal chemistry of lead-based copper oxide superconductors is discussed on the basis of their crystal data obtained by X-ray and neutron powder diffraction. The block layers of the quenched specimens of Pb₂Sr₂YCu₂O_y (Pb3212) and PbBaSrYCu₃O_y (Pb2212) consist of independent PbO and Cu layers, whereas those of the oxygen-annealed specimens of Pb2212 and (Pb, Cu) Sr₂ (Y, Ca) Cu₂O_y (Pb1212) contain double or single (Pb, Cu) O_x layers with disordered metal configurations. The structure of the block layers for oxygen-annealed Pb3212 varied with annealing conditions. Displacement of oxygen atoms from ideal positions in the (Pb, Cu) layer was considered to affect the crystal structure of Pb3212 and Pb2212.