Preparation of single crystal

Abstract

Abstract PURPOSE:To prevent the occurrence of cracks and prepare a piezoelectric single crystal having improved quality and reliability in good yield, by keeping the temperature of the piezoelectric single crystal formed by the pulling up method at 40 deg.C or above till the completion of the polarizing treatment. CONSTITUTION:A piezoelectric single crystal, e.g. lithium niobate or lithium tantalate single crystal, grown from a molten single crystal material by the pulling up method is annealed, and (i) both sides perpendicular to the Z-axis of the single crystal are cut at 40 deg.C or above, preferably 50-60 deg.C. Platinum electrodes are then attached to the resultant smooth sides and (ii) heated to 1,200 deg.C. A voltage, e.g. about 2V/cm, is applied across both the electrodes. The whole assembly is then annealed at a cooling rate of about 1 deg.C/min while kept under the voltage applied thereto to form the aimed polarized single crystal plate.

Inventors

• 👤 Tadao Komi
• 👤 小見　忠雄
• 👤 Yoshinori Okada
• 👤 義憲 岡田

Bibliographic Details