NEW ALLOTROPIC FORM OF SILICON

A new allotropic form of amorphous silicon with sp hybridization of th e valence electrons is discovered. The new material consists of linear chains of atoms. A small fraction of the atoms are in the sp(2) state . Acting as bridges, these atoms couple the linear chains into a singl e random network. This conclusion is based on an analysis of experimen tal data on the effect of annealing and ion implantation on the struct ure of the short-range order and the properties of amorphous-silicon f ilms obtained by different methods. (C) 1998 American Institute of Phy sics. [S0021-3640(98)00709-9].