シリカ類似構造のアルミノケイ酸塩ガラスにおける体積弾性率-体積関係

抄録

Density and elastic moduli of aluminosilicate glasses of composition R₂O-and MO⋅Al₂O₃⋅rSiO₂ were measured, where R=Li or (1/2Li+1/2Na), M=(1/2Mg+1/2Ca), and r=2 to 8. The volume per one mol of tetrahedral cations (Al and Si) is constant in each series, implying that bulk modulus K varies in proportion to V_ip^-4/3 (V_ip: ion-pair volume). However, because of the introduced R⁺ or M²⁺ ions occupying the interstices of silica-like cages, the log-log plots of K vs. V_ip gave a line of slope-4. It is proposed that one may use the relation KV_ip⁴=constant as a reference which represents the constitution of such stuffed silica type network glasses, though not explainable by a model in favor of the predominant contribution of anion-anion repulsion energy to the lattice energy.