DIELECTRIC MATERIAL EXHIBITING POLARIZATION TWIST, DIELECTRIC STRUCTURE IN WHICH POLARIZATION CAN BE CONTROLLED AND CAPACITOR AND PIEZOELECTRIC ELEMENT EACH USING SAME, AND CERAMIC AND CAPACITOR AND PIEZOELECTRIC ELEMENT EACH USING SAME

Title:

Document Type and Number:

WIPO Patent Application WO/2020/004670

Kind Code:

A1

Abstract:

[Problem] To provide: a dielectric material exhibiting polarization twist; a dielectric structure in which polarization can be controlled, and a capacitor and a piezoelectric element each using the dielectric structure; and a ceramic, and a capacitor and a piezoelectric element each using the ceramic. [Solution] A dielectric material exhibiting polarization twist, in which the concentration of vacancy of anions on X-site, which are introduced as the result of the formation of A-site vacancy, i.e., the deficiency of a metal located on A-site at each apical position of a cubic crystal or a pseudo-cubic crystal, is 1% or less, octahedrons of anions present in a perovskite structure are arranged with twisting an angle ω around the crystal axis of the cubic crystal or the pseudo-cubic crystal, and both of the angle ω and the polarization value vary upon the application of an electric field. In a ceramic represented by general formula: (A1(1-x+δ)/2A2(1-x-3δ)/2A3x□δ)BO3, the properties of the ceramic can be controlled by adjusting the combination of the amount δ of A-site vacancy and the amount x of A3.

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Inventors:

NOGUCHI YUJI (JP)
KITANAKA YUKI (JP)
NOMOTO HAYATE (JP)

Application Number:

PCT/JP2019/026162

Publication Date:

January 02, 2020

Filing Date:

July 01, 2019

Export Citation:

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Assignee:

UNIV TOKYO (JP)

International Classes:

C30B29/32; C01G29/00; C30B29/30; H01G4/08; H01G4/12; H01L41/187; H01L41/253

Foreign References:

JP2012099704A	2012-05-24
JP2013515353A	2013-05-02
JP2004508704A	2004-03-18
JP2010225705A	2010-10-07

Other References:

KITANAKA, YUUKI ET AL.: "Polarization twist in perovskite ferrielectrics", SCIENTIFIC REPORTS, vol. 6, no. 32216, 2016, pages 1 - 11
KITANAKA, YUUKI ET AL.: "Enhanced polarization properties of ferrielectric AgNb03 single crystals grown by Czochralski method under high-pressure oxygen atmosphere", JAPANESE JOURNAL OF APPLIED PHYSICS, vol. 55, 2016, pages 1 - 4
XU, QING ET AL.: "Effect of bismuth excess on ferroelectric and piezoelectric properties of a (Na0.5Bi0.5) TiO3-BaTiO3 composition near the morphotropic phase boundary", JOURNAL OF ALLOYS AND COMPOUNDS, vol. 471, 2009, pages 310 - 316, XP025994419, DOI: 10.1016/j.jallcom.2008.03.078