Single crystal growth of the pyrochlores R2Ti2O7 (R=rare earth) by the optical floating-zone method

Abstract

We report a systematic study on the crystal growth of the rare-earth titanates R2Ti2O7 (R=Gd, Tb, Dy, Ho, Y, Er, Yb and Lu) and Y-doped Tb2−xYxTi2O7 (x=0.2 and 1) using an optical floating-zone method. High-quality single crystals were successfully obtained and the growth conditions were carefully optimized. The oxygen pressure was found to be the most important parameter and the appropriate ones are 0.1–0.4MPa, depending on the radius of rare-earth ions. The growth rate is another parameter and was found to be 2.5–4mm/h for different rare-earth ions. X-ray diffraction data demonstrated the good crystallinity of these crystals. The basic physical properties of these crystals were characterized by the magnetic susceptibility and specific heat measurements.