朗道序参量理论计算液气流体系统的临界指数  

CALCULATING CRITICAL EXPONENTS FOR THE LIQUID-GAS SYSTEM VIA LANDAU'S THEORY OF ORDER PARAMETERS

作　　者：岑理相[1] CEN Lixiang(College of Physical Science and Technology, Siehuan University, Chengdu Sichuan 61006)

机构地区：[1]四川大学物理科学与技术学院,四川成都610065

出　　处：《物理与工程》2018年第2期26-28,共3页Physics and Engineering

基　　金：教育部高等学校物理学类专业教学指导委员会高等学校热力学与统计物理课程教学研究项目;中外热力学与统计物理课程教材比较研究;JZW-16-RT-07

摘　　要：本文针对朗道序参量理论处理液气流体系统出现的临界点以下液、气两相热力学势不对称这一困难,提出可以根据液气两相在平衡共存时化学势相等,研究沿两相共存曲线系统的吉布斯函数与序参量的关系及其临界行为。论文进一步演示了应用朗道理论计算该体系临界指数的具体过程,结果显示所得到的临界指数与朗道理论处理磁性系统所得的临界指数一致。论文研究弥补了目前"热力学与统计物理"教材中朗道序参量理论计算液气流体系统临界指数的空缺。Based on the equality of the chemical potentials between the two phases of the liquid and gas when they were in equilibrium,an approach is proposed to explore the Gibbs function and the order parameter along the coexistence curve,especially their relation in the vicinity of the critical point.This method overcomes the difficulty in applying the Landau theory to the phase transition of the critical point of the liquid-gas system owing to the asymmetry of the thermodynamic potentials between the gas and the liquid.Detailed calculations of the critical exponents for the specified system are then illustrated following the Landau＇s theory,which recovers the known result obtained from the magnetic system by Landau＇s theory.Our study makes up the vacancy in the textbook of＂thermodynamics and statistical physics＂about how to calculate critical exponents for the liquid-gas system by the Landau＇s theory of order parameters.

关 键 词：序参量 连续相变 临界指数 吉布斯函数 

分 类 号：O414[理学—理论物理]