Lattice dilatation of small silicon crystallites - implications for amorphous silicon

The lattice constant, d, of polycrystalline, hydrogenated silicon with a mean crystallite size less than 100 Å shows an expansion which increases with decreasing crystallite size, reaching a limiting value of Δd/d₀ ≈ 0.9 ? 1.2% for a crystallite size of about 30 Å. Implications of this result for some properties of amorphous silicon are briefly discussed.