材料期刊网

The thermal behavior of (14-x)SrCO3-xCaCO(3)-24CuO system has been investigated using combined differential thermal analysis (DTA) and X-ray diffraction (XRD) measurements to get a better understanding of solid-state chemical changes resulting in the synthesis of spin-ladder compound Sr14-xCaxCu24O41. In the temperature region 900-1000 degreesC, the DTA curves present one and two endothermic peaks for xless than or equal to5.6 and xgreater than or equal to8.4, respectively. XRD measurements demonstrated that for xless than or equal to5.6, the solid-state reaction consists of three stages and leads to the formation of the single-phase Sr14-xCaxCu24O41. It is found that both XRD and DTA methods can be employed independently to determine the composition or temperature region in which the pure phase forms. (C) 2004 Elsevier B.V. All rights reserved.