Synthesis of Large Single Crystals Within the Zr - Fe - Si System*

The synthesis of large single crystals of intermetallic silicides from a metal flux is challenging, owing to the poor solubility of silicon in many of the traditional fluxes at low temperatures. Accordingly, single crystal syntheses of several compounds within the Zr - Fe - Si system from a gallium flux were investigated. Zr$_4$Fe$_4$Si$_7$, a member of the well-known V-phase family of compounds, forms as silver lustrous rods. Successful growths yielded crystals with dimensions up to 12.1 mm by 0.14 mm by 0.14 mm, large enough to perform the first transport measurements of this compound. We grew for the first time single crystals of the hexagonal Laves phase ZrFe$_{1.5}$Si$_{0.5}$, which has previously only been reported in the polycrystalline form. Two previously unreported phases, including the silver lustrous rods Zr$_{2-x}$Fe$_4$Si$_{12-y}$, have been discovered as single crystals within this system. The composition of all phases was verified with powder and single crystal x-ray diffraction. Our group is currently investigating the growth of similar compounds using the methods developed for this system.