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AssigneeJfe Mineral Company, Ltd.
InventorsKeiichiro Nakamura, Kazuhiko Echizenya
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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.
A method for producing a solid solution piezoelectric single crystal ingot containing a relaxor having a composition formula of Pb(B1, B2)O3 and lead titanate having a composition of PbTiO3, using a Bridgman method, the production method comprising continuously feeding a raw material, which has a maximum particle size of 3 mm or less and contains the relaxor and the lead titanate, into a crucible for growth so that a concentration of the lead titanate is substantially constant in a growth direction of single crystal, and a variation range of the concentration is ±0.5 mol % or less over a length of 100 mm or more in the growth direction of single crystal,
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