Improving the multicaloric properties of Pb(Fe0.5Nb0.5)O3 by controlling the sintering conditions and doping with manganese

Designing multicaloric single-phase materials with combined electro- and magnetocaloric effects is still at its initial stage and presents a number of challenges. One of the main challenges encountered so far is to reduce the excessive electrical conductivity, which leads to the appearance of Joule heating that might completely degrade the electrocaloric response. In this work, multicaloric Pb(Fe0.5Nb0.5)O-3 material was successfully prepared exhibiting pronounced electrocaloric effect above room temperature and maximum magnetocaloric effect at cryogenic temperature. The conductivity was suppressed by controlling the sintering temperature. The ceramic sintered at 1000 degrees C exhibits maximum electrocaloric effective cooling of 0.88 degrees C at 28 degrees C and maximum magnetocaloric effect of 0.14 degrees C at - 271 degrees C. The caloric properties can be further improved by doping Pb(Fe0.5Nb0.5)O-3 with manganese. In comparison to the undoped sample, Pb(Fe0.5Nb0.5)O-3 doped with 0.5 mol% of manganese exhibits three times higher maxima of electrocaloric effective cooling (2.47 degrees C at 80 degrees C) and magnetocaloric temperature change (0.44 degrees C at -271 degrees C).