Spherical HfO2 particles obtained by hydrolysis of hafnium tert-butoxide

✍ Scribed by M. Ocaña; M. Andres; C.J. Serna

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 621 KB
• Volume: 79
• Category: Article
• ISSN: 0927-7757
• DOI: 10.1016/0927-7757(93)80172-b

✦ Synopsis

The preparation of spherical particles of amorphous HfO, by hydrolysis of hafnium tert-butoxide in both the aerosol phase and in ethanolic solutions is described. The first procedure yielded unagglomerated spheres with a mean diameter of 0.2 pm and narrow size distribution, whereas smaller spheres (0.15 pm) with some agglomeration were obtained by hydrolysis in solution. On heating, both samples crystallize into monoclinic hafnia, the temperature of crystallization being lower in the sample prepared by hydrolysis of aerosols (535°C) than in the one obtained in solution (620°C). The lower temperature of crystallization in the former is ascribed to the high content of organic impurities detected in the sample.