Get access

A Route Forwards to Narrow the Performance Gap between PZT and Lead-Free Piezoelectric Ceramic with Low Oxygen Partial Pressure Processed (Na0.5K0.5)NbO3

Authors

  • Keisuke Kobayashi,

    Corresponding author
    1. Materials R&D Department, R&D Laboratory, Taiyo Yuden Company, Ltd., Takasaki, Gunma, Japan
    • Center for Dielectric Studies, Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania
    Search for more papers by this author
  • Yutaka Doshida,

    1. Materials R&D Department, R&D Laboratory, Taiyo Yuden Company, Ltd., Takasaki, Gunma, Japan
    Search for more papers by this author
  • Youichi Mizuno,

    1. Materials R&D Department, R&D Laboratory, Taiyo Yuden Company, Ltd., Takasaki, Gunma, Japan
    Search for more papers by this author
  • Clive A. Randall

    1. Center for Dielectric Studies, Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania
    Search for more papers by this author

Author to whom correspondence should be addressed. e-mail: kei-koba@jty.yuden.co.jp

Abstract

Reduced atmosphere firing of (Na0.5K0.5)NbO3 (NKN) ceramics opens up an important opportunity for lead-free piezoelectric materials; one of the promising applications is base metal cofired multilayer actuators. Here, we extend an investigation on the effects of reduced atmosphere firing (PO2 = 10−10 atm) on the piezoelectric properties and associated point defects in NKNLiF ceramics. To access the domain dynamics contribution to the converse piezoelectric properties and consider point defects in the sintered ceramics, Rayleigh analysis and thermal stimulated depolarization current (TSDC) were used. The piezoelectric properties and Rayleigh analysis of NKNLiF ceramics demonstrated that the intrinsic and extrinsic piezoelectric response is essentially independent of firing atmosphere. Furthermore, reduced fired ceramic was found to have much higher resistivity than in the air-fired case. From the TSDC analysis, the space charge in the reduced fired ceramic was considered to be much smaller than in the air-fired ceramic, implying that the alkali volatilization was suppressed in reduced fired NKNLiF ceramic.

Ancillary