Zr在αU中的溶解焓和过剩熵的第一性原理计算研究
First-Principles Calculations of the Solution Enthalpy and the Excess Entropy of Zr in αU
屈哲昊 1冯伟 2高春来3
作者信息
- 1. 中国原子能科学研究院反应堆工程技术研究所,北京 102413
- 2. 中国原子能科学研究院核工程设计研究所,北京 102413
- 3. 淮阴工学院数理学院,江苏淮安 224001
- 折叠
摘要
针对U-Zr相图中富U端Zr在αU中的固溶度曲线所需的溶解焓和过剩熵,分别进行了第一性原理计算并与实验数据进行了对比分析.对于Zr-αU固溶体转变为δUZr2时对应的溶解焓和过剩熵,采用SQS模型得到每个Zr原子对应的结果为1.437 eV/Zr atom和1.060 kB/Zr atom,采用disorder模型得到每个Zr原子对应的结果为1.420 eV/Zr atom和0.732 kB/Zr atom.基于实验数据,分析拟合得到的每个Zr原子的溶解焓为-0.823±0.712 meV/Zr atom,过剩熵为5.880±9.976 kB/Zr atom.对比理论计算和拟合实验数据的结果发现,振动熵对固溶度的影响不可忽略,并且理论和实验数据相差较大的原因可能与理论计算中设置的δUZr2中Zr的位置与实验中的具体结构位置参数不尽相同有关.
Abstract
The solution enthalpy and the excess entropy of Zr in αU have been calculated based on the first principles calculations in order to achieve U-rich solubility curves for U-Zr phase diagram.The solution enthalpy and the excess entropy of the Zr atom corresponding to Zr-αU transforming from solution state into δUZr2 are 1.437 eV/Zr atom and 1.060 kB/Zr atom by the SQS model,and they are 1.420 eV/Zr atom and 0.732 kB/Zr atom by the disorder structure for δUZr2.But based on the experimental data,the fitted solution enthalpy and excess entropy are-0.823±0.712 meV/Zr atom and 5.880±9.976 kB/Zr atom,respectively.The comparison between the theoretical calculations and the experimental fitting results show that the effect of the vibrational entropy on solubility can not be ignored.This discrepancy between the theoretical results and the experimental data may be related to the fact that the positions of Zr in δUZr2 in the theoretical calculations are not well consistent with the specific structural parameters of the the experimental samples.
关键词
第一性原理/溶解焓/过剩熵/振动熵Key words
first-principles/solution enthalpy/excess entropy/vibrational entropy引用本文复制引用
出版年
2024
NETL
NSTL
万方数据