C, N在γFe中扩散激活能的计算

在固体与分子经验电子理论基础上提出了用结构弛豫模型计算C,N在γFe中的扩散激活能.首先,加以约束,间隙原子挤入鞍点位置,电子的杂化台阶保持不变.然后,解除约束,原子在库仑排斥力作用下松弛,达到平衡.第一步所需的能量可以由第二步来部分地补偿.用这种方法,计算了C,N在γFe中的扩散激活能,与实验值的相对误差＜5%,这是目前同类理论得到的较好结果.

Computation of Diffusion Activation Energies of C, N in γFe

A structure relaxation model based on the empirical electron theory of solids and molecules is developed to compute the diffusion active energies of C, N in γFe. First, adding a restriction, the lattice maintains rigidity when solute atom migrates to the saddle point. In this step, the hybridization classes of every atom do not change. Then, the restriction is loosed and the atoms are relaxed under the coulomb repulsive forces. It is supposed that the energy needed in the first step would be compensated partly by the second step. In this way, the diffusion active energies of C, N in γFe are computed. Compared with the experiment data, the relative errors are less than 5%, which are good results in the computation of activation energy of diffusion.