title: Theory of electric creep and electromechanical coupling with domain evolution for non-poled and fully poled ferroelectric ceramics.
abstract: Unlike mechanical creep with inelastic deformation, electric creep with domain evolution is a rarely studied subject. In this paper, we present a theory of electric creep and related electromechanical coupling for both non-poled and fully poled ferroelectric ceramics. We consider electric creep to be a time-dependent process, with an initial condition lying on theD(electric displacement) versusE(electric field) hysteresis loop. Both processes are shown to share the same Gibbs free energy and thermodynamic driving force, but relative to creep, the hysteresis loop is just a field-dependent process. With this view, we develop a theory with a single thermodynamic driving force but with two separate kinetic equations, one for the field-dependent loops in terms of a Lorentzian-like function and the other for the time-dependentDin terms of a dissipation potential. We use the 0°-90° and then 90°-180° switches to attain these goals. It is demonstrated that the calculated results are in broad agreement with two sets of experiments, one for a non-poled PIC-151 and the other for a fully poled PZT-5A. The theory also shows that creep polarization tends to reach a saturation state with time and that the saturated polarization has its maximum at the coercive field.
authors.affiliation: School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092, People's Republic of China; Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, NJ 08903, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xia
authors.affiliation: Department of Mechanical and Aerospace Engineering , Rutgers University , New Brunswick, NJ 08903 , USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Aerospace Engineering and Applied Mechanics , Tongji University , Shanghai 200092 , People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhong
authors.affiliation: Department of Mechanical and Aerospace Engineering , Rutgers University , New Brunswick, NJ 08903 , USA.
authors.forename: George J
authors.identifier: 0000-0003-1543-1535
authors.initials: GJ
authors.lastname: Weng
keywords: dissipation potential; domain evolution; electric creep; electromechanical coupling; ferroelectric ceramics; thermodynamic driving force