Properties of M1-M2-Si-Al-O-N Glasses (M1 = La or Nd, M2 = Y or Er)

Mixed lanthanide cation oxynitride glasses have been prepared in the M1 - M2 - Si-Al-O-N systems where M1 = La or Nd and M2 = Y or Er. The densities (rho), Young's moduli (E), microhardnesses (H-v), glass transition temperatures (T-g), dilatometric softening temperatures (T-dil) and coefficients of thermal expansion (CTE) of 13 glasses were determined. The molar volume values (MV) calculated kfrom density data, E, H-v, T-g, T-dil, and CTE values were all found to vary linearly with the effective cation field strength arising from the M1 and M2 modifier cations. Least squares intercept and slope values are presented which correlate each property to effective cation field strength together with error values which arise from glass and specimen preparation and measurement inconsistencies. These linear correlations clearly indicate that the overall glass structure remains the same for each of the thirteen glasses with only the modifier cation(s) having any influence. This influence appears to be a cross-linking effect, the strength of which increases as the effective cation field strength of the Ml, M2 modifiers increases.