Preliminaries -- Contents -- 1. Introduction -- 2. Synthesis of nanocrystalline powders -- 2.1. Gas phase synthesis -- 2.2. Plasma chemical technique -- 2.3. Precipitation from colloid solutions -- 2.4 Thermal decomposition and reduction -- 2.5. Milling and mechanical alloying -- 2.6. Synthesis by detonation and electric explosion -- 2.7. Ordering in non-stoichiometric compounds -- 2.8. Synthesis of high-dispersed oxides in liquid metals -- 2.9. Self-propagating high-temperature synthesis -- 4. Evaluation of the size of small particles -- 4.1. Electron microscopy -- 4.2. Diffraction -- 4.3. Superparamagnetism, sedimentation, photon correlation spectroscopy and gas absorption -- 5. Properties of isolated nanoparticles and nanocrystalline powders -- 5.1. Structural and phase transformations -- 5.2. Crystal lattice constant -- 5.3. Phonon spectrum and heat capacity -- 5.4. Magnetic properties -- 5.5. Optical properties -- 6. Microstructure of compacted and bulk nanocrystalline materials -- 6.1. Interfaces in compacted materials -- 6.2. Study of nanocrystalline materials by means of positron annihilation technique -- 6.3. Structural features of submicrocrystalline metals prepared by severe plastic deformation -- 6.4. Nanostructure of disordered systems -- 7. Effect of the grain size and interfaces on properties of bulk nanomaterials -- 7.1. Mechanical properties -- 7.2. Thermal and electric properties -- 7.3. Magnetic properties -- 8. Conclusions.