The Effect of Nitrogen on The Crystallization Behavior of Barium-Silicon-Aluminum-Oxygen-Nitrogen Oxynitride Glasses (Phase Separation, Crystal Growth)

Oxynitride glasses in the Ba-Si-Al-O-N system which were clear, homogeneous, and free of metallic inclusions were produced using gel-derived oxide glass batches and electronic-grade Si(,3)N(,4). Nitrogen was found to act as a nucleating agent in the oxynitride glasses by inducing separation into two distinct phases via a nucleation and growth mechanism, with the droplet phase being enriched in nitrogen. The droplet phase was the first to crystallize, followed by the growth of crystals into the matrix by an interface-controlled process. The final microstructure consisted mainly of interlocking clusters of lath-shaped crystals with some residual glass dispersed among the crystals. The crystalline phase was found to be a complex solid solution with the hexacelsian crystal structure whose composition can be given as BaAl(,2-(x+y))Si(,2+(x+y))O(,8-y)N(,y)(OH)(,x), where (x + y) (LESSTHEQ) 1.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Ceramics Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Tredway, William Kent

• Engineering, Materials Science

Identifier

(UMI)AAI8701637

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71708