现代连续相变理论在玻璃分相中的应用

Application of the Modern Continuous Phase Transition Theory to Phase Separation in Glasses

玻璃分相区中存在一临界点,在此临界点的转变属于连续相变范畴。通过本文的讨论表明。对二组元玻璃系统的分相,可以用现代连续相变理论描述。在临界点附近区域内,其分相曲线为以临界点为界,以两曲线方程:(x^l-x_c)/x_c=A[(T_c-T)/T_c]^(1/3),(x^(l′)-x_c)/x_c=A′[(T_c-T)/T_c]^(1/3)来表达。这里 A、A′为二组元系统分相曲线的普适常数。本文中对 Li_2O-SiO_2,Na_2O-SiO_2,BaO-SiO_2系统分相实验值的拟合结果是 A=-1.8305;A′=2.3551。相应的计算曲线与实验值符合较好。

There is a critical point in all glass phase separation boundaries.The phasetransition at this point belongs to continuous phase transition.By the discussionin this paper,it has been known that the phase separation in binary glass systemscan be described by the modern continuous phase transition theory.The equationsfor the immiscible curves at the two sides of the neighborhood of the critical pointare:(x′-x_c)/x_c=A[(T_c-T)/T_c]^(1/3),(x′-x_c)/x_c=A′[(T_c-T)/T_c](1/3).Here A andA′are universal constants of immiscible curves.In this paper,the fitting results ofA and A′from Li_2O-SiO_2,Na_2O-SiO_2,BaO-SiO_2 system′s experimental data ofphase separation are A=-1.8305:A′=2.3551.The corresponding calculated curvesfit the experimental data very well.Further research will be done for getting moreaccurate universal A and A′.