RELATIONSHIP BETWEEN TC AND HOLE CONCENTRATION IN BI2SR2CACU2O8+DELTA

Structure and electrical property are studied in the quenched Bi2Sr2Ca(1 - x)Nd(x)Cu2O8 + delta system. The quenched samples with 0 less-than-or-equal-to x less-than-or-equal-to 1 have a single phase of the Bi2Sr2CaCu2O8 + delta structure, as do the furnace-cooled samples. The oxygen concentration decreases slightly by about 0.05 in the chemical formula upon quenching from 800-degrees-C into liquid nitrogen. The T(c) remains a constant (approximately 90K) for x less-than-or-equal-to 0.15, and decreases linearly with x in the range of 0.15 less-than-or-equal-to x less-than-or-equal-to 0.45, and superconductivity disappears for x greater-than-or-equal-to 0.45. The result for the quenched system, if x is shifted by +0.1 in it, agrees very well with that for the furnace-cooled Bi2Sr2Ca(1 - x)Nd(x)Cu2O8 + delta and Bi2Sr(2 - x)Nd(x)CaCu2O8 + delta systems. The relationship between the T(c) and the hole concentration in [Cu - O] is confirmed to be universal in both the quenched and the furnace-cooled Bi2Sr2CaCu2O8 + delta systems.