Compositions for high power piezoelectric ceramics

US8216488B2 · kind B2 · utility

Assignee

• Piezotech LLC · US

Inventor

• De Liufu · Westfield, US

Key dates

• Filing date: May 5, 2011
• Grant date: Jul 10, 2012
• Expiry date: May 5, 2031

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B2235/79
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A class of ceramic compositions according to the formula Pb(1-z)Mz(Mn1/3Sb2/3)x(ZryTi1-y)1-xO3 where M is selected to be either Sr or Ba, x is selected to be between 0.01 and 0.1, y is selected to be between 0.35 and 0.55, and z is selected to be between 0.01 and 0.10. In some embodiments of the above composition, one or more dopants is added to the compositions. The dopant(s) may be selected from the group comprising: PbO, CeO2, SnO2, Sm2O3, TeO2, MoO3, Nb2O5, SiO2, CuO, CdO, HfO2, Pr2O3, and mixtures thereof. The dopants can be added to the ceramic composition in individual amounts ranging from 0.01 wt % to up to 5.0 wt %. The preferred ceramic compositions exhibit one or more of the following electromechanical properties: a relative dielectric constant (∈) of between 1200 and 2000, a mechanical quality factor (Qm) of between 1500 and 2800; a piezoelectric strain constant (d33) of between 250-450 pC/N, a dielectric loss factor (tan δ) of between 0.002-0.008 and a thickness electromechanical coupling coefficient (kt) of between 0.45 and 0.7.