Abstract

Due to the improvement of metal deposition techniques in the last ten years, high quality epitaxial metallic superlattices made from non soluble materials with different crystal structures and important lattice mismatches are now available for varied applications. One exciting aspect of this kind of superlattices, among others, is their novel elastic properties (different from those of the constituents or their eventual alloys) due to the lattice deformation caused by epitaxial stress. As an example, one can cite the average lattice expansion in the growth direction and the softening of the sound velocity that have been reported for Mo/Ni superlattices[1, 2]. The above papers have been chosen because, as we will see later, they illustrate some controversial interpretation of X-Ray diffraction data and sound velocity measurements.

© 1992 Optical Society of America