公开(公告)号：US11299818B2

公开(公告)日：2022-04-12

申请号：US16312109

申请日：2017-06-28

Applicant: JFE MINERAL COMPANY, LTD.

Inventor： Kazuhiko Echizenya

IPC: C30B11/04 ,  C30B11/02 ,  C30B29/32 ,  C30B11/00

Abstract: Provided is a method for producing a single crystal, wherein compositional variations and defects in the single crystal can be prevented and a single crystal having uniform characteristics in the growth direction can be produced at high yield. In this method for producing a single crystal, a PbTiO3-containing single crystal is produced by the vertical Bridgman technique, wherein the thickness of a melt layer containing the melt in a crucible is at least 30 mm.

公开(公告)号：US11155932B2

公开(公告)日：2021-10-26

申请号：US16621993

申请日：2018-07-06

Applicant: JFE MINERAL COMPANY, LTD.

Inventor： Keiichiro Nakamura ,  Kazuhiko Echizenya

IPC: C30B29/32 ,  C04B35/499 ,  C30B11/00 ,  C30B29/30 ,  H01L41/187

Abstract: A method for producing a piezoelectric single crystal ingot shows small variation in the concentration of PbTiO3 in the growth direction of single crystal. A complete solid solution-type piezoelectric single crystal ingot is produced by using the Bridgman method, including: filling a starting material, wherein a relaxor having a compositional formula Pb(B1, B2)O3 is blended with lead titanate having a composition PbTiO3 to give a preset composition, into a crucible for growth; heating to the melting temperature to give a melted liquid layer; then moving the crucible for growth toward the low temperature side; and thus starting one-direction solidification from the lower part of the crucible to thereby produce a single crystal. During solidification, the feedstock containing the relaxor and lead titanate having a maximum grain size ≤3 mm is continuously supplied into the crucible.