【作者】 刘彦平；

【导师】 欧阳义芳；

【作者基本信息】 广西大学 ， 理论物理， 2004， 硕士

【摘要】 利用金属元素的物理性质，运用最近导出的普适分析型嵌入原子模型[general analytic embedded atom method（GAEAM）]，计算了Fe、Ni、Ti、Al和Ba四种元素的表面能、体积模量、结构稳定性、空位形成能等物理性质和Fe-Al、Ni-Al、Ti-Al三个合金系中5个有序结构金属间化合物相的物理特性和点缺陷，得出了以下主要结论： 1．综合分析各种EAM模型的优缺点，在Johnson分析型EAM模型的基础上，提出一种普适分析型EAM理论（GAEAM）。此模型通过拟合元素的晶格常数、结合能、单空位形成能、弹性模量和Rose方程，可描述BCC、FCC和HCP结构元素和由不同结构金属所形成的金属间化合物的物理性质。 2．利用GAEAM模型计算了Fe、Ni、Ti和Al四种元素的表面能、弹性常数、结构稳定性、空位形成能等物理性质，计算结果与实验结果符合较好。 3．利用GAEAM模型计算了金属间化合物的物理性质。计算了这些有序结构晶体的晶格常数、合金结合能和弹性常数。计算结果和实验结果和其它理论结果符合较好。 4．利用GAEAM模型计算了这些有序合金的空位和反空位形成能。计算结果表明当FeAl、Fe₃Al、NiAl、Ni₃Al和TiAl有序合金偏离理想化学配比成分时出现的结构缺陷类型为，分别在各子晶格中出现反位置缺陷，与实验结果和其它理论结果相符合，其中NiAl的缺陷类广西人学硕十论文型与某些理论结果有所不同。5.本文利用GAEAM模型计算了Fe和Ba两种元素的表面形成能、弹 性常数、结构稳定性等物理性质和Fe一Ba二元合金的形成烩，其中本文对Ba的弹性常数，声子谱等热力学性质进行了计算和预测。更多还原

【Abstract】 The physical properties of elements can be easily calculated with general analytic embedded atom method (GAEAM). The low index surface energies, elastic constants, structural stabilities, vacancy formation energies for Fe, Ni, Ti, Al and Ba were calculated with the present GAEAM. The properties, such as point defect, for Fe-Al, Ni-Al, Ti-Al intermetallics were also studied. The results are following:1. Based on Johnson’s analytic EAM, a new General analytic embedded atom method (GAEAM) was developed in this paper. Using this GAEAM, the physical properties of 56 elements of BCC, FCC and HCP structure and intermetallics being made up of different structure metal, can be calculated by fitting cohesion energy, lattice constant, mono-vacancy formation energy and bulk modulus.2. By using the GEAM, we calculated the nono-vacancy formation energy , elastic constants, the stability of structure and the surface energy of Fe, Ni, Ti and Al. The calculated results are in agreement with the experiments available results and other theoretic results.3. We calculated the equilibrium lattice constant, cohesion energy and elastic constants of FeAl, Fe3Al, NiAl, Ni3Al and TiAl.4. The single point defects are calculated by using GEAM. The results ofcalculating show that the defect types are the antisite atoms on either sublattice for nonstoichiometry in FeAl, Fe3Al, NiAl, Ni3Al and TiAl. The results are in good agreement with the experimental data and other theoretic results.5. The GEAM model can be used simply, commonly, systematically in studying the physical properties and defects in elements and ordered compounds being made up of different structure metals. This is one of the characteristics different between the GEAM and other EAM theories.更多还原