NATURE AND EXTENT OF OXYGEN NONSTOICHIOMETRY IN BI2SR2CACU2O8+DELTA

被引：45

作者：

IRVINE, JTS

NAMGUNG, C

机构：

[1] Chemistry Department, University of Aberdeen, Aberdeen, AB9 2UE Scotland, Meston Walk

来源：

JOURNAL OF SOLID STATE CHEMISTRY | 1990年 / 87卷 / 01期

关键词：

D O I：

10.1016/0022-4596(90)90061-2

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Oxygen nonstoichiometry in Bi2Sr2CaCu2O8+δ has been investigated using a number of thermogravimetric and titrimetric techniques. Apparent discrepancies between the results obtained by different methods have been resolved and can be explained by consideration of the chemical processes involved in the analytical procedures. For samples prepared in air at 850°C and air quenched the total oxygen constant is 8.19 O per formula unit. Titrimetric measurements show that there are two components to the oxygen excess in Bi2Sr2CaCu2O8+δ. One, 0.14 O, leads to oxygen evolution on dissolution; the other, 0.05 O, retains its high oxidation state on dissolution. Thermogravimetric measurements also show that the oxygen excess consists of these two components. One part, 0.06 O per formula unit, can be removed by heating in air at temperatures just below melting and is easily reduced by hydrogen. The remainder, 0.13 O, is more difficult to remove, persisting after most of the bismuth and copper oxygens have been removed by hydrogen. © 1990.

引用

页码：29 / 34

页数：6

共 18 条

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