LiTaO₃ Single Crystal Growth by the Vertical Bridgman Technique

Abstract

Lithium tantalate, LiTaO 3 (LT), single crystal growth by the vertical Bridgman (VB) technique is attempt for the first time. In the present VB-LT technique, pure platinum crucibles are used in a furnace with a graphite heater and an argon atmosphere. One-hundred percent solidified crack-free VB-LT crystals are successfully grown by composing the initial melts with exactly congruent compositions. The fundamental technical issues for VB-LT growth are also clarified.

Vertical Bridgman Growth of 42°RY‐Oriented LiTaO3 Single Crystal

“…Then, the crucible was lowered at a constant rate of 2 mm h −1 and an LT crystal was grown from the seed, inheriting the seed′s crystal orientation. After the crucible containing the grown LT crystal had been removed from the VB furnace, the Pt crucible was destructively peeled away from the crystal, with the high ductility and the high malleability of the Pt itself permitting the grown crystal to be easily released in this manner . The crystal was then annealed at 1400 °C for 5 h in air.…”

“…After the crucible containing the grown LT crystal had been removed from the VB furnace, the Pt crucible was destructively peeled away from the crystal, with the high ductility and the high malleability of the Pt itself permitting the grown crystal to be easily released in this manner. [9,16] The crystal was then annealed at 1400°C for 5 h in air. The crystal growth process using the seed crystal and the raw material differed only in the addition of the raw material to the above process.…”

“…In this experiment, the same crystal growth VB furnace for LT single crystal growth shown in the literature was used. Figure shows a schematic of the setting of the crucible in the VB furnace.…”

“…We are investigating the vertical Bridgman (VB) technique for LT single crystal growth by a resistance‐heated power source system using a graphite heater, as it can lower cost and lower power consumption of the growth furnace compared to the conventional CZ technique for LT single crystal growth, which relies on an induction‐heating system using radio frequency power. We previously reported the successful growth of Z‐axis orientation and 25 mm in diameter LT single crystals using a full‐diameter seed crystal and a pure platinum (Pt) crucible . At the end of the same paper, we also introduced the successful growth of 42°RY‐LT and 50 mm in diameter LT single crystals by the same VB technique, noting that the details of their growth would be published in another paper.…”

“…We previously reported the successful growth of Z-axis orientation and 25 mm in diameter LT single crystals using a full-diameter seed crystal and a pure platinum (Pt) crucible. [9] At the end of the same paper, we also introduced the successful growth of 42°RY-LT and 50 mm in diameter LT single crystals by the same VB technique, noting that the details of their growth would be published in another paper.…”