Structural stability and electronic properties of LaO- and NiO2-terminated LaNiO3 (0 0 1) surface

LaO- and NiO2-terminated LaNiO3 (0 0 1) surfaces were investigated by first principle calculations. For NiO2-terminated surface, Ni atoms exhibit an abnormal relaxation. Larger surface rumpling emerges in the topmost layer of LaO termination, which is almost twice as large as that of NiO2 termination. LaO-terminated surface has the lowest surface energy and stable structure. Non-polar surfaces exhibit remarkably different electronic structures and more Ni atoms exposed to the surface will contribute to higher density of states at Fermi level, which provides a guide to grow novel ultra-thin heterostructures with controlled electronic state of metal ions.