Method of making coherent multilayer crystals

Claim 1

A process for forming a multilayer, superlattice crystal having parallel, ultrathin alternating layers of two different metal elements comprising: placing a substrate suitable for epitaxial growth into a vacuum vessel; removing the ambient gas from the vessel; establishing a pressure of sputtering gas of at least 5×10 -3 torr in the vessel; heating the substrate to about 150° to 450° C.; establishing two beams of sputtered atoms, one beam for each metal element of which the crystal is to be formed, the metals being elements which will grow epitaxially on each other; adjusting the thermal energy of the atoms in each beam so that the temperature of the atoms as they reach the substrate, is about the temperature of the surface of the substrate, whereby the atoms in the beam do not displace or eject atoms in layers already deposited on the surface but grow epitaxially on the layers to form a superlattice crystal structure; and alternately passing each beam of sputtered atoms over the the substrate to deposit alternate layers of the two metal atoms epitaxially on the surface and on each other, each layer being from 2 to 2500 angstroms in thickness, thereby forming a multilayer, superlattice crystal having parallel, ultrathin alternating layers of two different metal elements.