Absolute lattice parameter measurements of epitaxial layers

A method for obtaining the absolute lattice parameters of layered structures to an accuracy of a few units in 10 6 is described. A second motorized axis, for a reference crystal, is mounted onto a commercially available single‐axis goniometer, so that double‐crystal rocking curves can be combined with single‐crystal lattice parameter measurements. The rocking curves and lattice parameter measurements are obtained from the same high‐angle Bragg reflection, which results in this high degree of accuracy.