Anisotropic thermal expansion of monoclinic potassium lutetium tungstate single crystals Available to Purchase

The anisotropic thermal expansion of a single crystal of $KLu(WO4)2(KLuW)$⁠, obtained by the top-seeded solution growth method, has been investigated over a wide temperature range (50–600 °C). The linear thermal-expansion tensor has been determined and its principal $X$⁠, $Y$⁠, and $Z$ axes are in the [705], [010], and [107] crystallographic directions, respectively. The principal thermal-expansion coefficients $αI$⁠, $αII$⁠, and $αIII$ are $12.8×10−6$⁠, $7.8×10−6$⁠, and $22.2×10−6K−1$⁠, respectively. The principal axis with maximum thermal expansion (⁠$Z$ with $αIII=22.2×10−6$⁠) is located at 10.37° from the $c$ axis. In comparison with $KGd(WO4)2$ and $KYb(WO4)2$⁠, the thermal-expansion anisotropy of KLuW is weaker and therefore optical-quality crystals are easier to obtain than with KGdW and KYbW from a thermal-expansion standpoint.