The elastic properties of LaNbO/sub 4/

The measurement of single-crystal elastic properties is an important method of materials characterization. Elastic properties define intrinsically bulk behavior, but they also provide a microscopic insight into the dynamical behavior of the crystal lattice in relation to crystal structure and bonding. Moreover, they are particularly informative probes into the onset and the nature of a lattice instability and its role in inducing a phase transformation. On a macroscopic scale, stress-strain relationships, particularly those of an anisotropic kind, can be better understood and described in terms of the single-crystal elastic constants. The authors discuss the recent measurements on the elastic properties of a single crystal of LaNbO/sub 4/ to exemplify these points. This rather extensively studied double-cation oxide has a crystal structure in which isolated niobium-centered NbO/sub 4/ tetrahedra are linked by La ions