Magnetic and electronic properties of silicane with hydrogen vacancies on the surface

By using first-principles pseudopotential calculations, we investigate the magnetic and electronic properties of hydrosilicon honeycomb structure (silicane) with hydrogen vacancies on its surface. It is found that a single vacancy created on the nonmagnetic silicane can induce a magnetic moment of one μB. When a domain of vacancies is considered, the magnetization is determined by the size and geometry of the domain, and whether it is single- or double-sided. Compared with the energy band structure of silicane, the creation of domain causes very flat bands around the Fermi level and tends to reduce the band gap. It is interesting to find that the systems with single-sided domain all exhibit a band gap of about 1.0 eV while those of double-sided domain exhibit strong size dependence.