The correlation between dielectric permittivity and electrocaloric (EC) temperature change (ΔTEC) has been investigated in (1 − x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 (PMN–100xPT, with x = 0, 0.05, and 0.10) relaxor ferroelectric ceramics. At a given electric field, both peak temperatures, including the temperature of the permittivity peak (Tm) and the temperature of the maximum of the ΔTEC (TEC max) increase with increasing PT content. The peak of the dielectric permittivity is, regardless of the applied electric field, always at a higher temperature than is the TEC max, and the temperature gap between both maxima progressively increases with increasing applied DC bias. This is particularly true above the threshold field, which induces the long-range ordered ferroelectric state. The results, which are explained in terms of the electric field–temperature phase diagram of relaxor systems, thus reveal that Tm can only roughly mark the temperature of the upper boundary of the temperature–electric field window, where the EC responsivity (ΔTEC/ΔE) is the highest.
Relation between dielectric permittivity and electrocaloric effect under high electric fields in the Pb(Mg1/3Nb2/3)O3-based ceramics
Note: This paper is part of the Special Topic on Multicalorics.
Lovro Fulanović, Andraž Bradeško, Nikola Novak, Barbara Malič, Vid Bobnar; Relation between dielectric permittivity and electrocaloric effect under high electric fields in the Pb(Mg1/3Nb2/3)O3-based ceramics. J. Appl. Phys. 14 May 2020; 127 (18): 184102. https://doi.org/10.1063/5.0002096
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