Piezoelectric voltage constant and sensitivity enhancements through phase boundary structure control of lead-free (K, Na)NbO3-based ceramics. Issue 12 (September 2022)

• Record Type: Journal Article
• Authors: Lee, Min-Ku; Kim, Byung-Hoon; Lee, Gyoung-Ja
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 12(2022)
• Page Start: 4898
• Page End: 4906
• Publication Date: 2022-09
• Subjects: Lead-free piezoelectrics -- Accelerometer -- (K -- Na)NbO3-based ceramics -- Piezoelectric voltage constant -- Phase boundary structure; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2022.05.025
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The piezoelectric voltage constant ( g 33 ) is a material parameter critical to piezoelectric voltage-type sensors for detecting vibrations or strains. Here, we report a lead-free (K, Na)NbO3 (KNN)-based piezoelectric accelerometer with voltage sensitivity enhanced by taking advantage of a high g 33 . To achieve a high g 33, the magnitudes of piezoelectric charge constant d 33 and dielectric permittivity ε r of KNN were best coupled by manipulating the intrinsic polymorphic phase boundaries effectively with the help of Bi-based perovskite oxide additives. For the KNN composition that derives benefit from the combination of ε r and d 33, the value of g 33 was found to be 46.9 × 10 −3 V·m/N, which is significantly higher than those (20 – 30 × 10 −3 V·m/N) found in well-known polycrystalline lead-based ceramics including commercial Pb(Zr, Ti)O3 (PZT). Finally, the accelerometer sensor prototype built using the modified KNN composition demonstrated higher voltage sensitivity (183 mV/g) when measuring vibrations, showing a 29% increase against the PZT-based sensor (142 mV/g).