No abstract

The glass formation range in the system Zn0-B203-SiOt increases when 5% N 2 0 3 is added and then decreases with further Al2o3 additions. The acid resistivity of the glass also increases when AlzOJ is added. An observed increase in negative charge with A1 content until the system contains equal amounts of Al and Si (in forms of mole %) is explained by the formation of AIO; tetrahedra which substitute in the Si04 network. Alkaline-earth oxides cause a positive charge which compensates for the negative charge formed by &03. Antimony oxide and lanthanum oxide result in a negative charge in the glass. The formation of a negative or positive charge in the glass is thought to reflect the acidity or basicity of the glass, respectively.

No abstract

The glass formation range in the title system increases after 5% Al2O3 addition and then decreases with increasing Al2O3 content.