Growth of Lead Titanate (PbTiO₃) Single Crystals

Abstract

The phase diagram of PbO (massicot)-PbTiO₃ system in PbO rich region was determined by X-ray diffraction and DTA measurement. On the basis of this diagram, single crystals of perovakite-type PLTiO₃ were grown from the melt with PbO as flux. And it was also studied by using a mixture of PbO-H₃BO₃-PbTiO₃.
The following results were obtained.
(1) PbTiO₃ single crystals were tetragonal having the stoichiometric composition and the direction of the growth was [100].
(2) The largest PbTiO₃ single crystals (5mm×5mm×1mm) were obtained from the melt with the composition of PbO : PbTiO₃=(80-70):(20-30) by mole percent.
(3) There was no difference in crystal size between the crystals obtained by the cooling rate of 25°C/hr and that of 50°C/hr from the melt at 1100°C.
(4) The translucent or partial translucent PbTiO₃ single crystals were grown by adding 10 mole percent boric acid to the mixture of PbO:PbTiO₃=(80-70):(20-30).
(5) In PLO-H₃BO₃-PbTiO₃ system, the region of the composition for obtaining single crystals of PbTiO₃ was 10≤PbTiO₃≤35, 25≤PbO≤85 and 0≤H₃BO₃≤52 mole percent and the translucent or partial translucent single crystals were grown in the region of 10≤PbTiO₃≤30, 25≤PbO≤45 and 44≤H₃BO₃≤52 mole percent.