Na_(2)O–Li_(2)O–Al_(2)O_(3)–SiO_(2)–P_(2)O_(5)玻璃的结构与性能的分子动力学模拟

Structure and Properties of Na_(2)O–Li_(2)O–Al_(2)O_(3)–SiO_(2)–P_(2)O_(5)Glasses via Molecular Dynamics Simulations

磷硅酸盐玻璃因有着良好的生物活性和光学性能,已广泛用于生物材料、光纤等领域。运用分子动力学模拟方法研究Li_(2)O含量对Na_(2)O–Al_(2)O_(3)–SiO_(2)–P_(2)O_(5)玻璃的微观结构以及扩散性能影响,着重讨论了其微观结构与维氏硬度,扩散系数之间的关系。结果表明:玻璃的磷网络聚合度(Qp)随着Li_(2)O逐渐替代Na_(2)O而增加,硬度随着Qp的增加而增大。体系中Li^(+)的自扩散系数比Na^(+)大,即Li^(+)比Na^(+)更易扩散。Li^(+)的势垒随着Li2O增加而逐渐变小,Li_(2)O对Na_(2)O取代有益于Li^(+)扩散。

Phosphosilicate glasses are widely used in optical fiber,biological materials and other fields because of their excellent optical properties and biological activity.The influence of Li_(2)O content on the microstructure and diffusion properties of Na_(2)O–Al_(2)O_(3)–SiO_(2)–P_(2)O_(5)glass was investigated via molecular dynamics simulation,and the relationship among the microstructure,Vickers hardness and diffusion coefficient was analyzed.The results show that the degree of phosphorus network polymerization(Q^(P))increases with the substitution of Li_(2)O for Na_(2)O,and the hardness increases with the increase of Q^(P).The self-diffusion of Li^(+) ions is greater than that of Na^(+) ions,indicating that Li^(+) ions are easier to diffuse rather than Na^(+) ions.The potential barrier of Li^(+) ions decreases with the increase of Li_(2)O.Li_(2)O is beneficial to the substitution of Na_(2)O for the diffusion of Li^(+) ions.