Materials Research Bulletin, Vol.30, No.2, 193-199, 1995
Synthesis of Filmy ZrF4-BaF2 Glasses by Fluorination of Amorphous Oxide Gels
Filmy gels of xZrO2-(100-x)BaO compositions (x=100, 75, 60, 50 and 40) in mol% were prepared by a sol-gel process using zirconium n-butoxide and barium n-butoxide as starting materials. Dried gels of x=100, 75 and 60 were amorphous, while those of x=50 and 40 contained appreciable amounts of crystalline precipitates. The dried gels of x=100, 75 and 60 were fluorinated at 200 approximately 300-degrees-C using an HF or NF3 gas. Fluorination of the x=60 dried gel by NF3 at 250-degrees-C gave a filmy but monolithic 60ZrF4.40BaF2 glass. The obtained glass was characterized by X-ray diffraction, infra-red absorption, DTA and ESR. The X-ray halo pattern, IR absorption spectrum, glass-transition temperature and crystallization temperature of the glass coincided with those of a 60ZrF4.40BaF2 glass prepared by a conventional melting method.