Large electrocaloric strength in Sm/Mn co-doped BaTiO3 ceramics

Electrocaloric (EC) refrigeration, which employs ferroelectric (FE) ceramics as a working medium, is regarded as a promising green refrigeration technology that could potentially replace vapor-compression refrigeration. One of the principal considerations in EC application is the capacity to attain high EC strength near room temperature. In this work, we investigated the EC effect in Sm/Mn co-doped BaTiO3 [(Ba1-1.5xSmx)(Ti0.99Mn0.01)O3] ceramics. As the smallest trivalent ion that can totally occupy the A site, Sm3+ is not only capable of shifting the Curie temperature but also of optimizing the EC effect. Furthermore, the introduction of the Mn element into the matrix results in the formation of defect dipoles, which also serves to enhance the EC performance. Therefore, large EC strengths of Delta T/Delta E=0.49KmmkV-1 (@51 degrees C), 0.34KmmkV-1 (@39 degrees C) and 0.21KmmkV-1 (@30 degrees C) were, respectively, achieved in x=0.05-0.07 ceramics, demonstrating the potential for future refrigeration applications.