Thermal activation of ferroelectric switching

Abstract

By applying the theory of thermally activated nucleation to the switching of ferroelectric domains, a method is developed to experimentally obtain the value of both the activation enthalpy, ⌬H, and activation volume, V * , for the thermally activated process involved in ferroelectric switching. The method was applied to the switching of a soft lead zirconate titanate and values of ⌬H = ͑0.16± 0.02͒ eV and V * = ͑1.62± 0.16͒ ϫ 10 −25 m 3 were obtained at the coercive field. These values imply that the energy, ⌬U, required for the formation of switching nuclei is mainly supplied by the work done by the electric field. A comparison of these values with those obtained from theoretical considerations suggests that the switching is achieved by the sideways expansion of nuclei formed at the domain boundaries in the form of low amplitude and long wavelength fluctuations of the domain walls.

A constitutive model for thermo-electro-mechanical behavior of ferroelectric polycrystals near room temperature

“…In strain responses, the magnitude of actuation strain seems to decrease with increase in temperature at zero compressive stress, though it is not significant. The calculated variations of polarization hysteresis and strain butterfly responses over temperature at 0 MPa are qualitatively consistent with experimental observations of Chong et al (2008), Kounga et al (2008), Kim (2010), Yimnirun et al (2007), and aixACCT (www.aixacct.com, see Senousky et al (2009)). But the behavior of calculated strain butterfly responses at larger compressive stresses À100 or À150 MPa is totally different from that at 0 MPa.…”

Electric field and temperature scaling of polarization reversal in silicon doped hafnium oxide ferroelectric thin films

“…The critical nucleation field differs from region to region; while in general, increases in both external applied field and temperature can facilitate it to be achieved. The latter is related to the thermal-activation mechanism [25,26]. At very low temperatures (e.g.…”

Statistical electric field and switching time distributions in PZT 1Nb2Sr ceramics: Crystal- and microstructure effects

“…The higher the spontaneous polarization component inverse to the field direction, the higher is the switching rate. 52 Antiparallel orientations of a field vector and a spontaneous polarization vector imply high energy, so the release of this energy promotes the 180 switching.…”