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US5079197A Expired / Lapsed US ⏱️ 0.0 years remaining

Ferroelectric ceramics

Assignee: Mitsui Chemicals Inc
•
Filing: 1990-10-19
•
Granted: 1992-01-07
•
Expires: 2010-10-19
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Abstract

Abstract The present invention relates to Perovskite ferroelectric ceramics comprising a Perovskite solid solution represented by the formula Pb.sub.1-(3/2)a M.sub.a {(Ni.sub.1/3 Nb.sub.2/3).sub.1-b (Zn.sub.1/3 Nb 2/3 ) b } x Ti y Zr z O 3 wherein M is at least one element selected from the group consisting of La and Nd, x+y+z is 1, said Perovskite solution containing MnO 2 . When compared with known ferroelectric ceramics, the ferroelectric ceramics according to the invention has a larger piezoelectric constant d and also a sufficiently high Curie temperature Tc, while having a mechanical quality factor Qm practically equal to that of the known ferroelectric ceramics. Accordingly, the ferroelectric ceramics according to the invention exhibit excellent characteristics when used in application such as a driving part of an actuator, for example, of an ultrasonic motor where mechanical resonance of the material used is utilized.

Inventors

  • 👤 Yoshihisa Ushida
  • 👤 Hiroshi Mase

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 05:42
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/49; C04B35/46; H; H10; H10N; H10N30/00; H10N30/80; H10N30/85; H10N30/853

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 98 words
A ferroelectric ceramic that is a Perovskite solid solution, which comprises a solid solution represented by the formula: Pb.sub.1-(3/2)a M.sub.a {(Ni.sub.1/3 Nb.sub.2/3).sub.1-b (Zn.sub.1/3 Nb.sub.2/3).sub.b }.sub.x Ti.sub.y Zr.sub.z O.sub.3 wherein M is at least one element selected from the group consisting of La and Nd, x+y+z is 1, a is from 0.005 to 0.03, b is from 0.5 to 0.95, x is from 0.1 to 0.4, y is from 0.3 to 0.5 and z is from 0.2 to 0.5, and containing MnO 2 in an amount of from 0.3 to 1.0% by weight based on the Perovskite solid solution.
Claim 2
Dependent Claim 98 words
A ferroelectric ceramic that is a Perovskite solid solution, which comprises a solid solution represented by the formula: Pb.sub.1-(3/2)a M.sub.a {(Ni.sub.1/3 Nb.sub.2/3).sub.1-b (Zn.sub.1/3 Nb.sub.2/3).sub.b }.sub.x Ti.sub.y Zr.sub.z O.sub.3 wherein M is at least one element selected from the group consisting of La and Nd, x+y+z is 1, a is from 0.005 to 0.03, b is from 0.5 to 0.95, x is from 0.1 to 0.4, y is from 0.3 to 0.5 and z is from 0.2 to 0.5, and containing MnO 2 in an amount of from 0.3 to 1.0% by weight based on the Perovskite solid solution.
Claim 3
Dependent Claim 15 words
The ferroelectric ceramic as claimed in claim 1 wherein M in the formula is La.
Claim 4
Dependent Claim 15 words
The ferroelectric ceramic as claimed in claim 1 wherein M in the formula is Nd.
Claim 5
Dependent Claim 104 words
An actuator comprising a ferroelectric ceramic that is a Perovskite solid solution, wherein said ferroelectric ceramic comprises a solid solution represented by the formula: Pb.sub.1-(3/2)a M.sub.a {(Ni.sub.1/3 Nb.sub.2/3).sub.1-b (Zn.sub.1/3 Nb.sub.2/3).sub.b }.sub.x Ti.sub.y Zr.sub.z O.sub.3 wherein M is at least one element selected from the group consisting of La and Nd, x+y+z is 1, a is from 0.005 to 0.03, b is from 0.5 to 0.95, x is from 0.1 to 0.4, y is from 0.3 to 0.5 and z is from 0.2 to 0.5, and containing MnO 2 in an amount of from 0.3 to 1.0% by weight based on the Perovskite solid solution.
Claim 6
Dependent Claim 104 words
An actuator comprising a ferroelectric ceramic that is a Perovskite solid solution, wherein said ferroelectric ceramic comprises a solid solution represented by the formula: Pb.sub.1-(3/2)a M.sub.a {(Ni.sub.1/3 Nb.sub.2/3).sub.1-b (Zn.sub.1/3 Nb.sub.2/3).sub.b }.sub.x Ti.sub.y Zr.sub.z O.sub.3 wherein M is at least one element selected from the group consisting of La and Nd, x+y+z is 1, a is from 0.005 to 0.03, b is from 0.5 to 0.95, x is from 0.1 to 0.4, y is from 0.3 to 0.5 and z is from 0.2 to 0.5, and containing MnO 2 in an amount of from 0.3 to 1.0% by weight based on the Perovskite solid solution.
Claim 7
Dependent Claim 14 words
The actuator as claimed in claim 4 wherein M in the formula is La.
Claim 8
Dependent Claim 14 words
The actuator as claimed in claim 4 wherein M in the formula is Nd.

References Cited (Backward Citations)

JPS54159697A Cited
US4765919A Cited
US4749668A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-01-06 1995-07-08 1996-01-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-01-06 1999-07-08 2000-01-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-01-06 2003-07-08 2004-01-07 $7700.00 Window Closed / Lapsed

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