Aging in the ferroic random-field Ising model system strontium-barium niobate

Abstract

Large aging effects, investigated via temporal dependences of the dielectric response, are found to be inherent in the uniaxial ferroelectric relaxor systems $\mathrm{SBN}:\mathrm{Cr}$ and $\mathrm{SBN}:\mathrm{Ce}$. The results are discussed on the basis of domain coarsening and domain-wall pinning effects. Owing to the different charge disorder induced by the ${\mathrm{Cr}}^{3+}$ and ${\mathrm{Ce}}^{3+}$ dopants, a fundamental difference between both systems is established. While $\mathrm{SBN}:\mathrm{Ce}$ shows only a weak breaking of ergodicity, the $\mathrm{SBN}:\mathrm{Cr}$ system experiences true ergodicity breaking.