大势相场模型的不平衡热力学基础
Jin Zhang1, James A Warren2, Peter W Voorhees1
1Northwestern University, Department of Materials Science and Engineering, Evanston, Illinois 60208, USA.
Physical review. E
|March 19, 2025
概括
大势相场模型正确地最小化了赫尔姆霍尔茨自由能量,确保了质量保存. 这种热力学一致性对于准确的相场建模和模拟至关重要.
科学领域:
- 热力学是一种热力学.
- 材料科学 材料科学 材料科学
- 计算建模 计算建模
背景情况:
- 热力学一致的相场模型对于准确的模拟是必不可少的.
- 自由能量函数的选择显著影响模型的行为和预测.
研究的目的:
- 为了确定相场模型的适当的自由能量函数,这些模型保存质量.
- 在相场模拟中分析赫尔姆霍尔茨自由能量和大潜力的行为.
主要方法:
- 在大势相场模型中强加质量保存.
- 分析赫尔姆霍尔茨自由能量和大潜力的最小化条件.
主要成果:
- 大势相场模型被证明可以在质量保存下最小化赫尔姆霍尔茨自由能量.
- 在这个模型中,赫尔姆霍尔茨自由能量随着时间的推移而单调地减少,与大潜力不同.
- 将巨大潜力最小化导致同化学条件,违反质量保存.
结论:
- 大电位公式适用于需要质量保存的相场模型.
- 了解自由能源的功能行为是开发准确和一致的热力学模型的关键.
相关概念视频
Thermodynamic Potentials
749
Thermodynamic potentials are state functions that are extremely useful in analyzing a thermodynamic system. They have dimensions of energy. The four important thermodynamic potentials are internal energy, enthalpy, Helmholtz free energy, and Gibbs free energy. These thermodynamic potentials can be expressed using two of the following variables: pressure, volume, temperature, and entropy. These two variables are expressed as the rate of change of the thermodynamic potential with respect to other...
749
Potential-Energy Criterion for Equilibrium
497
Potential energy or potential function plays an essential role in determining the stability of a mechanical system. If a system is subjected to both gravitational and elastic forces, the potential function of the system can be expressed as the algebraic sum of gravitational and elastic potential energy. If the system is in equilibrium and is displaced by a small amount, then the work done on the system equals the negative of the change in the system's potential energy from the initial to...
497
Maxwell's Thermodynamic Relations
2.4K
Maxwell's thermodynamic relations are very useful in solving problems in thermodynamics. Each of Maxwell's relations relates a partial differential between quantities that can be hard to measure experimentally to a partial differential between quantities that can be easily measured. These relations are a set of equations derivable from the symmetry of the second derivatives and the thermodynamic potentials.
All thermodynamic potentials are exact differentials. Therefore, their second-order...
All thermodynamic potentials are exact differentials. Therefore, their second-order...
2.4K
Cell Potential and Free Energy
39.2K
Thermodynamics of a Redox Reaction
Thermodynamics is the branch of physics dealing with the relationship between heat and other forms of energy. In an electrochemical cell, chemical energy is converted into electrical energy.
Thus, a link can be predicted between cell potential, free energy change, and the equilibrium constant for the reaction. Cell potential can also be measured as the oxidant or the reducing strength, and similar acid-base strength measures are reflected in equilibrium...
Thermodynamics is the branch of physics dealing with the relationship between heat and other forms of energy. In an electrochemical cell, chemical energy is converted into electrical energy.
Thus, a link can be predicted between cell potential, free energy change, and the equilibrium constant for the reaction. Cell potential can also be measured as the oxidant or the reducing strength, and similar acid-base strength measures are reflected in equilibrium...
39.2K
Energy Diagrams - II
4.6K
Energy diagrams are important to understand the dynamics of a system. The topology of an energy diagram helps illustrate the equilibrium points of the system.
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The...
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The...
4.6K
The Nernst Equation
39.9K
Nonstandard Reaction Conditions
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ÃÂÃÂGÃÂð and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with EÃÂúcell = +0.291 V and ÃÂÃÂGÃÂð = âÃÂÃÂ56.2 kJ is spontaneous.
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ÃÂÃÂGÃÂð and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with EÃÂúcell = +0.291 V and ÃÂÃÂGÃÂð = âÃÂÃÂ56.2 kJ is spontaneous.
39.9K


