Nanophase metals, ceramics and other solids, are made of the same atoms as their more common forms, but the atoms are arranged in nanometer-size clusters, which become the constituent grains, or building blocks, of these new materials.

Whereas the grains in conventional materials range from microns to millimeters in diameter and contain several billion atoms, those in nanophase materials are less than 100 nanometers in diameter and contain fewer than tens of thousands of atoms.