Float zone growth and characterization of Pr_(9.33)(SiO_4)_6O_2 and Sm_(9.33)(SiO_4)_6O_2 single crystals with an apatite structure

摘要

Single crystals of apatite-type prasodymium silicate (Pr_(9.33)(SiO_4)_6O_2) and samarium silicate (Sm_(9.33)(SiO_4)_6O_2) with high oxide ionic conductivity have been grown by the floating zone method. The as-grown crystals of Pr_(9.33)(SiO_4)_6O_2 and Sm_(9.33)(SiO_4)_6O_2 are geen and orange, respectively, and both crystals are transparent,. The crystlas do not contain inclusions, low-angel grain boundaries or twin structures but the samarium silicate crystals contian a few cracks perpendicular to the c-axis whereas the praseodymium silicate crystals are crack-free.