Crystalline nanometer-scale Ge particles have been synthesized by pulsed laser ablation and introduced into a Si host matrix, grown by chemical beam epitaxy from disilane. The proposed structure of the Ge:Si composite films consists of Ge nanocrystals surrounded by a thin epitaxial Si shell that passivates the surface of the Ge nanocrystallite. The Ge nanocrystallites are randomly oriented with respect to each other and are randomly distributed in a polycrystalline or amorphous Si matrix. Ge nanoparticles with and without Si matrix were deposited directly on C-coated TEM grid and imaged by high resolution TEM. Ge:Si composites deposited on Si wafers were characterized by RBS.