Zirconate Pyrochlore Frustrated Magnets: Crystal Growth by the Floating Zone Technique

This article reviews recent achievements on the crystal growth of a new series of pyrochlore oxides—lanthanide zirconates, which are frustrated magnets with exotic magnetic properties. Oxides of the type $A_2$ $B_2$ O ${}_7$ (where $A=$ Rare Earth, $B=$ Ti, Mo) have been successfully synthesised in single crystal form using the floating zone method. The main difficulty of employing this technique for the growth of rare earth zirconium oxides $A_2$ Zr ${}_2$ O ${}_7$ arises from the high melting point of these materials. This drawback has been recently overcome by the use of a high power Xenon arc lamp furnace for the growth of single crystals of Pr ${}_2$ Zr ${}_2$ O ${}_7$ . Subsequently, large, high quality single crystals of several members of the zirconate family of pyrochlore oxides $A_2$ Zr ${}_2$ O ${}_7$ (with $A=$ La → Gd) have been grown by the floating zone technique. In this work, the authors give an overview of the crystal growth of lanthanide zirconates. The optimum conditions used for the floating zone growth of $A_2$ Zr ${}_2$ O ${}_7$ crystals are reported. The characterisation of the crystal boules and their crystal quality is also presented.