Electronic and magnetic properties of Al adsorption on α-uranium (0 0 1) surface: Ab initio calculations

First-principles calculations based on density functional theory (DFT) with the generalized gradient approximation have been performed to study the aluminum (Al) adsorption on the (0 0 1) surface of α-uranium (α-U). The geometric, electronic and magnetic properties have been investigated at coverages of 0.25 and 0.5 monolayer. The results show that the quasi-trigonal sites are preferred at both coverages. The bonding of Al with U is found to be metallic, which mainly arises from the mixing of Al 3sp and U 5f states. A ferromagnetic phase is determined for the bare α-U (0 0 1) surface, while the adsorption of Al on the surface significantly perturbs the spin arrangement pattern and reduces the local magnetic moment, leading to a ferrimagnetic phase on the α-U (0 0 1) surface at the coverage of 0.5 monolayer. However, the Al overlayer is paramagnetic. Generally, the spin-polarization has negligible effects on the geometric and electronic properties of Al atoms on the α-U (0 0 1) surface.