Using ab initio total energy calculations with the full-potential linearized augmented plane wave method,the possibilities of magnetism in one-dimensional In and Tl wires were explored and their properties as the function of geometric structures were studied.The results suggest that the linear In and Tl wires show magnetization at the equilibrium bond distance with magnetic moments of 0.71 and 0.67 μB/atom,respectively.Allowing ions to relax,the wires were deformed as zigzag structures,but no dimerization occurs.The zigzag wires also exhibit spontaneous magnetization,although the magnetic moments are lower than those of straight wires.
The scaling behaviour of surface roughness evolution of microcrystalline silicon (μc-Si:H) films prepared by veryhigh frequency plasma-enhanced chemical vapour deposition (VHF-PECVD) has been investigated by using a spectroscopic ellipsometry (SE) technique. The growth exponent β was analysed for the films deposited under different pressures Pg . The results suggest that films deposited at Pg = 70 Pa have a growth exponent β about 0.22, which corresponds to the definite diffusion growth. However, abnormal scaling behaviour occurs in the films deposited at Pg = 300 Pa. The exponent β is about 0.81 that is much larger than 0.5 of zero diffusion limit in the scaling theory. The growth mode of μc-Si:H deposited at Pg = 300 Pa is clearly different from that of μc-Si:H at Pg = 70 Pa. Monte Carlo simulations indicate that the sticking process and the surface diffusion of the radicals are two key factors to affect the growth mode under different pressures. Under Pg = 300 Pa, β>0.5 is correlated with the strong shadowing effect resulting from the larger sticking coefficient.
