A novel route to synthesize cubic ZrW2−xMoxO8 (x=0–1.3) solid solutions and their negative thermal expansion properties
✍ Scribed by Ruiqi Zhao; Xiaojing Yang; Huiliang Wang; Jingsa Han; Hui Ma; Xinhua Zhao
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 665 KB
- Volume
- 180
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
Cubic ZrW 2Àx Mo x O 8 (c-ZrW 2Àx Mo x O 8 ) (x ¼ 0-1.3) solid solutions were prepared by a novel polymorphous precursor transition route. X-ray diffraction (XRD) analysis reveals that the solid solutions are single phase with aand b-ZrW 2 O 8 structure for 0pxp0.8 and 0.9pxp1.3, respectively. The optimum synthesis conditions of ZrWMoO 8 are obtained from differential scanning calorimetry-thermal gravimetric analysis (DSC-TGA), XRD and mass loss-temperature/time curves. Following the above experience, the stoichiometric solid solutions of c-ZrW 2Àx Mo x O 8 (x ¼ 0-1) are obtained within 1 wt% of mass loss. The relationships of lattice parameters (a), phase transition temperatures (T c ) and instantaneous coefficients of thermal expansion (a i ) against the content x of Mo are discussed based on the variation of order degree parameters of ZrW 2Àx Mo x O 8 .