Current activities in cooling research focus on solid-state cooling, based on caloric effects such as electrocaloric (EC), where the entropy of polar material changes with the applied electrical field¹. Currently, the relaxor ferroelectric (1-x)Pb(Mg_1/3Nb_2/3)O₃–xPbTiO₃ (PMN–100xPT) is one of the most promising inorganic EC materials^2,3. Namely, PMN–10PT exhibits an EC temperature change of 3.45 K at an electric field of 160 kV cm^-1 at 127 °C⁴. Previously, we investigated the feasibility of using PMN–10PT-based EC cooling elements in high-radiation environments such as medical accelerators, nuclear reactors, and space technologies⁵. We found that the dielectric, ferroelectric and EC properties of PMN–10PT remained almost unchanged upon exposure to a mixed field of neutrons and γ-rays at doses higher than the largest expected neutron irradiation in CERN⁶. By manganese doping of PMN–10PT, the temperature range of the peak EC response could be broadened and shifted closer to room temperature⁷.
In this contribution, we study how neutron and γ-irradiation influence the EC properties of aliovalently doped PMN–10PT ceramics. We prepared acceptor (Mn, 1 mol%) and donor (La, 1 mol%) doped PMN–10PT ceramic by mechanochemical synthesis and sintering at 1200 °C for 2 hours. The ceramics were irradiated in the research reactor TRIGA Mark II ⁸ with doses of 10¹⁶ cm^-2  and 10¹⁷ cm^-2 of 1 MeV equivalent neutron fluence for silicon and γ-rays at 145 kGy and 1200 kGy. In the contribution, we discuss the influence of irradiation on crystal structure, microstructure, dielectric, ferroelectric and EC properties of Mn- and La-doped PMN–10PT.