一种合成HgBa_2Ca_2Cu_3O_（8＋δ）超导体的新方法

A NEW METHOD FOR THE SYNTHESIS OF HgBa_2Ca_2Cu_3O_(8+δ)

采用加压烧结工艺在１０～３０ＭＰａ压强下合成了超导化合物ＨｇＢａ_２Ｃａ_２Ｃｕ_３Ｏ_（８＋δ）。样品的ＸＲＤ、磁化率和电阻测量结果表明：这种方法制备的Ｈｇ系超导样品的起始转变温度在１３０Ｋ以上，样品主要由ＨｇＢａ_２Ｃａ_２Ｃｕ_３Ｏ_（８＋δ）（即Ｈｇ－１２２３相）组成。由经验得知：在１０～３０ＭＰａ压强范围内，压力变化对Ｈｇ系超导体的起始转变温度无明显影响，但烧结过程中的升温速率对样品制备十分重要。

The superconducting compound Hg-Ba-Ca-Cu-O was synthesized by a sintering technique with a pressure of 10￣30MPa. The results of XRD analysis, AC magnetic susceptibility and resistivity measurements show that the major phase is Hg-1223 and the onset transition temperature is above 130K. The pressure-effect on onset transition temperature in the pressure range of 10￣30MPa is not observed. But the heating rate during the solid state reaction process is very important in the synthesis of the Hg system superconductors.