Kroupa A, Káňa T, Buršík J, Zemanová A, Šob M
Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic.
Phys Chem Chem Phys. 2015 Nov 14;17(42):28200-10. doi: 10.1039/c5cp00281h. Epub 2015 Mar 31.
A method for modelling of size-dependent phase diagrams was developed by combining the semiempirical CALPHAD method and ab initio calculations of surface stresses for intermetallic phases. A novel approach was devised for the calculation of surface energy, free of systematic errors from the selection of different parameters of the software (e.g. number of the k-points) and for handling layered structures and off-stoichiometric slabs. Our approach allows the determination of complex size-dependent phase diagrams of systems with intermetallic phases, which was not possible up to now. The method was verified for the modelling of the phase diagram of the Ni-Sn system and basic comparison with rare experimental results was shown. There is reasonable agreement between the calculated and experimental results. The modelling of size-dependent phase diagrams of real systems allows the prediction of phase equilibria existing in nanosystems and possible changes in material properties. There is a need for such knowledge and the existence of reliable data for simpler systems is crucial for further application of this approach. This should motivate future experimental work.
通过将半经验的CALPHAD方法与金属间相表面应力的从头算相结合，开发了一种尺寸依赖相图的建模方法。设计了一种新颖的表面能计算方法，该方法没有因软件不同参数（例如k点数量）的选择而产生的系统误差，并且能够处理层状结构和非化学计量平板。我们的方法能够确定具有金属间相的系统的复杂尺寸依赖相图，而这在以前是不可能的。该方法通过对Ni-Sn系统相图的建模进行了验证，并与稀少的实验结果进行了基本比较。计算结果与实验结果之间存在合理的一致性。对实际系统尺寸依赖相图的建模能够预测纳米系统中存在的相平衡以及材料性能可能发生的变化。对于此类知识存在需求，并且对于更简单系统而言，可靠数据的存在对于该方法的进一步应用至关重要。这应该会推动未来的实验工作。
