Stability of the Tl-1223 phases

被引：17

作者：

Aselage, TL ^{[1
]}

Venturini, EL ^{[1
]}

Voigt, JA ^{[1
]}

Miller, DJ ^{[1
]}

机构：

[1] ARGONNE NATL LAB,ARGONNE,IL 60439

来源：

JOURNAL OF MATERIALS RESEARCH | 1996年 / 11卷 / 07期

关键词：

D O I：

10.1557/JMR.1996.0205

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The thermodynamic stability of TlBa2Ca2Cu3O9-y (1223) and substitutionally related phases has been studied by performing extended high-temperature anneals in a two-zone furnace. This approach allows for independent control of each of the thermodynamic variables: the oxygen and thallous oxide partial pressures [P(O-2) and P(Tl2O)], the sample temperature, and the sample composition. P(Tl2O) determines which of several superconducting phases form in the unsubstituted Tl-Ba-Ca-Cu-O system. TlBa2Ca2Cu3O9-y is stable only within a narrow window of P(Tl2O). Partially replacing Tl with Pb and Ba with Sr substantially increases the stability of the 1223 phase. The composition (TlxPb0.5) (Sr1.6Ba0.4)Ca2Cu3O9-y yields only the 1223 phase under two-zone conditions when P(Tl2O) exceeds a lower bound. The stability of Pb- and Sr-substituted 1223 relative to the 1212 phase is related to the substitutional stoichiometry, rather than P(Tl2O).

引用

页码：1635 / 1644

页数：10

共 28 条

[21] UNIFORM AND FLEXIBLE 24-METER SUPERCONDUCTING TAPE OF SILVER-SHEATHED TL0.5PB0.5BA0.4SR1.6CA2CU3O8.2 [J].