| Summary: | This paper reports on the influence of sintering additives CuO and MgO on the recently developed lead-free electrocaloric (EC) material Ba<sub>0.82</sub>Sr<sub>0.18</sub>Sn<sub>0.065</sub>Ti<sub>0.935</sub>O<sub>3</sub> (BSSnT-18-6.5). Details on the sintering behavior and the resulting microstructure of bulk ceramic samples prepared through solid-state synthesis and their dielectric, ferroelectric, and electrocaloric properties are presented. On the one hand, the addition of CuO (<i>x</i><sub>CuO</sub> = 2%) significantly reduced the sintering temperature from 1400 °C to 1150 °C. On the other hand, the addition of MgO (<i>x</i><sub>MgO</sub> = 1%) dramatically reduced the average grain size from 40 µm to 0.4 µm, leading to an increase in dielectric breakdown strength from 4.4 V µm<sup>−1</sup> to 7.7 V µm<sup>−1</sup>. Thus, BSSnT-18-6.5 with the addition of MgO to bulk ceramic samples could achieve maximum EC temperature changes (|Δ<i>T</i><sub>EC</sub>|) of 0.27 K around 30 °C with almost no aberration within a broad temperature range from 5 °C to 50 °C under an applied electric field change of 5 V µm<sup>−1</sup>. The results show the potential of this material for the fabrication of multilayer ceramic (MLC) components for future electrocaloric applications.
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