Anisotropic thermal expansion of LiB₃O₅

Abstract

The anisotropic thermal expansion of LiB3O5 has been studied along the principal crystallographic directions over the temperature range of 17 to 790 degrees C by means of high-temperature X-ray powder diffraction. This orthorhombic crystal exhibits strongly anisotropic expansion with coefficients of 108.2*10-6 K-1 for (100), 33.6*10-6 K-1 for (010) and -88.0*10-6 K-1 for (001) at 50 degrees C. The coefficients tend to zero when the temperature approaches the crystal's peritectic reaction point.