Silicon carbide, SiC, thick films over mullite.

Author(s)

Inacio Regiani

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT)
• Defense date: 2001-11-19

Examining board members

Milton Ferreira de Souza; José Carlos Bressiani; Antonio Carlos Hernandes; José de Anchieta Rodrigues; Roberto Tomasi

• Advisor: Milton Ferreira de Souza

Abstract

Crystalline silicon carbide, SiC, films were deposited on mullite by atmospheric pressure chemical vapor deposition (CVD) method. The characteristic of substrate surface determinate if the film will be dense or porous, while the deposition temperature defines its crystalinity and nucleation rate in film formation. During the mullite substrate preparation process for film deposition, it was observed a whisker formation phenomenon when the piece was doped with 3%mol of rare earth. The growth phenomenon of these whiskers was studied systematically to its characterization and comprehension of its formation mechanism. The addiction of rare earth promote a reduction in mullitization temperature and the formation of whiskers with a composition that alumina / silica ration was 1.3, one of the lowest one ever observed. (AU)