LAUSR

Abstract The calculations of spin effects in 20 Si n O 2 n + m nanoclusters with 10 ⩾ m ⩾ 5 and m ⩾ 1 are presented. They include search for the equilibrium atomic structure, the calculations of electron spectra and the energy of different spin orderings. It was found that all Si n O 2 n + m clusters have spin moments, which are located on radical O atoms at the cluster surface. Long radical-to-radical distance weakens their exchange interaction, so energy differences between ferro-, ferri-, and antiferromagnetic states are of 0.01 eV or lower, gaining 0.046 eV only in Si 6 O 13 . We analyze this magnetism in terms of electron spectra and individual radical groups. Its similarity to popular molecular magnets based on organic radicals is noticeable. The stability of these Si n O 2 n + m clusters in O2 atmosphere, as well as their relation to silicon technology, is of particular interest for spintronics.