Piezoelectric Characteristics of 0.55Pb(Ni1/3Nb2/3)O3-0.45Pb(Zr,Ti)O3 Ceramics with Different MnO2 Concentrations for Ultrasound Transducer Applications.

Myeongcheol Kang,Lae-Hyong Kang

doi:10.3390/ma12244115

Abstract

In this study, we investigate the piezoelectric characteristics of 0.55Pb(Ni1/3Nb2/3)O3-0.45Pb(Zr,Ti)O3 (PNN-PZT) with MnO2 additive (0, 0.25, 0.5, 1, 2, and 3 mol%). We focus on the fabrication of a piezoelectric ceramic for use as both actuator and sensor for ultrasound transducers. The actuator and sensor properties of a piezoelectric ceramic depend on the piezoelectric strain coefficient d and piezoelectric voltage coefficient g, related as g = d/εT. To increase g, the dielectric constant εT must be decreased. PNN-PZT with MnO2 doping is synthesized using the conventional solid-state reaction method. The electrical properties are determined based on the resonant frequencies and vibration modes measured by using an impedance analyzer. The MnO2 addition initially improves the tetragonality of the PNN-PZT ceramic, which then saturates at a MnO2 content of 1 mol%. Therefore, the dielectric constant and piezoelectric coefficient d33 steadily decrease, while the mechanical properties (Qm, Young’s modulus), tanδ, electromechanical coupling coefficient k, and piezoelectric voltage coefficient g were improved at 0.5–1 mol% MnO2 content.

Highlights

Piezoelectric materials have attracted considerable interest for various applications such as multi-layer ceramic actuator, transducer, sensor and actuator applications, and for analyses on fundamental science
We investigated the piezoelectric characteristics of 0.55Pb(Ni1/3 Nb2/3 )O3 0.45Pb(Zr,Ti)O3 according to the MnO2 additive content (0, 0.25, 0.5, 1, 2, and 3 mol%)
The MnO2 addition initially improved the tetragonality of the PNN-PZT ceramic, which saturated at a MnO2 content of 1 mol%

Summary

Introduction

Piezoelectric materials have attracted considerable interest for various applications such as multi-layer ceramic actuator, transducer, sensor and actuator applications, and for analyses on fundamental science. Lead-based piezoelectric ceramics such as Pb(Zr,Ti)O3 (PZT) have been extensively used in electrical devices because of their excellent piezoelectric properties [1]. The policies suggesting lead elimination have triggered studies on alternative compounds such as (K 0.44 Na0.52 Li0.04 )-(Nb0.86 Ta0.10 Sb0.04 )O3 (KNL-NTS) [2]. The lead-based compositions have exhibited higher piezoelectric performances than those of the lead-free compositions such as KNL-NTS. Many piezoelectric ceramic compositions of the ternary system have been reported as the ternary system has a larger morphotropic phase boundary (MPB) area than that of a secondary system such as PZT. Lead-based relaxor ferroelectrics have a general formula of Pb(B’ B”)O3

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