Glassy freezing dynamics was investigated in BaZr0.5Ti0.5O3 (BZT50) ceramic samples [1,2] by means of dielectric spectroscopy in the frequency range 0.001 Hz–1 MHz at temperatures 10 < T < 300 K. From measurements of the quasistatic dielectric polarization in bias electric fields up to ∼28 kV/cm it has been found that a ferroelectric state cannot be induced, in contrast to the case of typical relaxors. This suggests that—at least for the above field amplitudes—BZT50 effectively behaves as a dipolar glass, which can be characterized by a negative value of the static third order nonlinear permittivity. The relaxation spectrum has been analyzed by means of the frequency-temperature plot, which shows that the longest relaxation time obeys the Vogel-Fulcher relation τ = τ0exp[E0/(T − T0)] with the freezing temperature of 48.1 K, whereas the corresponding value for the shortest relaxation time is ∼0 K, implying an Arrhenius type behavior. By applying a standard expression for the static linear permittivity of dipolar glasses and/or relaxors the value of the Edwards-Anderson order parameter q(T ) has been evaluated. It is further shown that q(T ) can be described by the spherical random bond-random field model of relaxors [3].
References
[1]. T. Maiti, R. Guo, and A. S. Bhalla, J. Appl. Phys. 100, 114109 (2006).
[2]. D. Wang, J. Hlinka, A. A. Bokov, Z.-G. Ye, P. Ondrejkovic, J. Petzelt, and L. Bellaiche, Nat. Commun. 5, 5100 (2014).
[3]. C. Filipic, Z. Kutnjak, R. Pirc, G. Canu, J. Petzelt, Phys. Rev. B 93, 224105 (2016).