Gohivar R K, Yadav S K, Koirala R P, Adhikari D
Central Department of Physics, Tribhuvan University, Kritipur, Nepal.
Department of Physics, Mahendra Morang Adarsh Multiple Campus, Tribhuvan University, Biratnagar, Nepal.
Heliyon. 2021 Mar 30;7(3):e06613. doi: 10.1016/j.heliyon.2021.e06613. eCollection 2021 Mar.
Temperature-dependent interaction parameters of Redlich-Kister (R-K) polynomials for Li-Mg alloy in liquid phase have been optimized using experimental data in the framework of linear and exponential models. These parameters have then been used to compute the thermodynamic properties (excess Gibbs free energy of mixing, enthalpy of mixing and activity) and structural property (concentration fluctuations in the long-wavelength limit) of the alloy at temperatures 1000 K, 1300 K, 1600 K, 1900 K, and 2200 K. The negative values of excess Gibbs free energy of mixing computed using linear T-dependent parameters increases with the rise in the temperature of the system beyond 1000 K while the same physical quantity computed using the exponential T-dependent interaction parameters decreases with the rise in temperatures and does not show any unusual trends up to 2200 K. Similar behavior has been found in the case of other thermodynamic and structural functions. The unusual behavior that appears in the thermodynamic and structural functions computed using linear T-dependent parameters can be eliminated if these functions are computed using exponential T-dependent parameters.
利用线性和指数模型框架下的实验数据，对液相中锂镁合金的Redlich-Kister（R-K）多项式的温度依赖相互作用参数进行了优化。然后，这些参数被用于计算该合金在1000 K、1300 K、1600 K、1900 K和2200 K温度下的热力学性质（混合超额吉布斯自由能、混合焓和活度）以及结构性质（长波极限下的浓度涨落）。使用与温度呈线性关系的参数计算得到的混合超额吉布斯自由能的负值，在系统温度超过1000 K时随温度升高而增加，而使用与温度呈指数关系的相互作用参数计算得到的相同物理量则随温度升高而降低，并且在2200 K之前未显示出任何异常趋势。在其他热力学和结构函数的情况中也发现了类似的行为。如果使用与温度呈指数关系的参数来计算这些函数，那么使用与温度呈线性关系的参数计算得到的热力学和结构函数中出现的异常行为就可以消除。
