4. (La, Sr) 2CaCu2O6の結晶構造と超電導発現機構について考察
1992 年 34 巻 5 号 p. 298-304
詳細
1992 年 34 巻 5 号 p. 298-304
Superconducting La1-xSrxCaCu2O6 samples with x in the range of 0.1≤x≤0.4 were synthesized by means of O2-HIP (hot isostatic press) technique. Superconducting properties were optimized at the composition of La1.8Sr0.2CaCu2O6, when the sample was O2 HIP annealed for 50h at 1070°C in the mixture of 80%-Ar and 20%-O2 gas of the total pressure of 100MPa. A joint neutron x-ray diffraction study was carried out to analyze both cation ordering and oxygen stoichiometry. This revealed the prefernital occupation of Ca for 2a site and of both La adn Sr for 4e site. A comparison of the structure of La1.8Sr0.2CaCu2O6 with those of non-superconducting or weakly superconducting doped samples suggests structural differences that may be responsible for the observed differences in behavior.
