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Influence of TiO 2 on Properties of Glasses in the System K 2 O–PbO–SiO 2 –TiO 2 and Its Relation to Structure
Author(s) -
RAO Bh. V. JANAKIRAMA
Publication year - 1963
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1963.tb11691.x
Subject(s) - dielectric , refractive index , softening point , materials science , mineralogy , softening , oxygen , dissipation factor , analytical chemistry (journal) , chemical engineering , chemistry , composite material , chromatography , organic chemistry , optoelectronics , engineering
By a progressive weight percent substitution of TiO 2 for SiO 2 at various rations of concentration of K 2 O and PbO, the entire region of glass formation in the quaternary system K 2 O–PbO–SiO 2 –TiO 2 was covered with 51 glass compositions. The properties of these glasses were determined and studied with respect to the role of TiO 2 in the system. The results indicated that the dielectric constant increased progressively with increasing TiO 2 concentration whereas the dissipation factor showed an overall decrease, when measured at 1 Mc and 25°C. Density and the refractive index increased progressively with increasing TiO 2 concentration but deviated from the additive relation. Chemical durability, expansivity, and softening temperature vs. composition curves showed definite inflections. The effect of TiO 2 on oxygen packing indicated that Ti 4+ strengthens the network in lower concentrations and weakens the network in higher concentrations in this system. It appears to be likely that Ti 4+ changes its coordination number form 4 to 6.