FLAPW方法研究δ-钚(001)面的性质

采用 FLAPW(全势线性缀加平面波)方法,在广义梯度近似(GGA)、反铁磁(AFM)下研究了δ-钚(001)面的性质.计算得到的表面能系数和功函数分别为0.08 eV/(A)2和3.15 eV,接近其近邻元素α-铀的实验值(0.094 eV/(A)2和3.4～3.9 eV).与体相原子相比,表层原子由于近邻原子数目的减少,5f-5f和5f-6d轨道波函数重叠、杂化几率降低,5f电子定域化特性增强,局部磁矩增大.表层原子向内收缩2.70%,然而,由于表面弛豫能很小,δ-钚(001)面相当稳定.

An all-electron FLAPW study of property of the (001) surface of δ-Pu

The full potential linear a.u.gmented plane wave method(FLAPW) is used to study the (001) surface of δ-Pu in the generalized-gradient approximation(GGA)and antiferromagnetic(AFM)configuration. Our calculated surface energy coefficient and work function are 0.08 eV/A~2 and 3.15 eV, respectively, which is in agreement with experiment values of 0.094 eV/A~2 and 3.4～3.9 eV for α-uranium. For the surface atoms, due to the reduced nearest neighbors, the opportunity of 5f-5f overlap and 5f-6d hybridization is decreased, 5f electrons appear to be more localized with enhanced local magnetic moment. Upon relaxation, the distance between the top layer and the next layer is found to decrease by 2.7% compared to the corresponding interlayer distance in the bulk. However, the low surface relaxation energy indicates that (001) surface of δ-Pu is rather stable.