Thermal decomposition of HfCl4 as a function of its hydration state

✍ Scribed by E. Barraud; S. Bégin-Colin; G. Le Caër; F. Villieras; O. Barres

• Book ID: 104029552
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 417 KB
• Volume: 179
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2006.02.027

✦ Synopsis

The thermogravimetric behavior of HfCl 4 powders with different hydration states has been compared. Strongly hydrated powders consist of HfOCl 2 Á nH 2 O with n44. Partially hydrated powders consist of particles with a HfCl 4 core and a hydrated outerlayer of HfOCl 2 Á nH 2 O with n in the range of 0-8. Hydrated powders decomposed at temperature lower than 200 1C whereas the decomposition of partially hydrated powders was completed at a temperature of around 450 1C. The observed differences in decomposition temperature is related to the structure of HfOCl 2 Á nH 2 O, which is different if n is higher or smaller than 4 and leads to intermediate compounds, which decompose at different temperatures.