Tunable pyroelectricity, depolarization temperature and energy harvesting density in Pb(Lu0.5Nb0.5)O3-xPbTiO3 ceramics

Abstract The ferroelectric to antiferroelectric (FE-AFE) phase boundary design based on orthorhombic AFE phase and tetragonal FE phase is an effective method to develop high-performance pyroelectric materials due to the complete release of large electrical polarization in FE-AFE phase transition. Herein, we report the phase structure evolution in (1-x)Pb(Lu0.5Nb0.5)O3-xPbTiO3 (abbreviated as PLNT100x) ceramic system based on the relationship of tolerance factors versus electronegativity differences. The composition/temperature effects on FE-AFE phase transition behavior, pyroelectricity, depolarization temperature (Td) and energy harvesting performance were investigated systematically. Obviously, PLNT system displays superior pyroelectric characteristics as well as high Td. The maximum pyroelectric peak was 4.50 μC·cm−2·K − 1 over a wide temperature range from 28 °C to 167 °C. In addition, the obtained maximum pyroelectric energy harvesting density was 1.66 J/cm3 which was much higher than the currently reported values, indicating a potential candidate for pyroelectric energy conversion applications. Based on the modified Ginzburg−Landau−Devonshire (GLD) phenomenology, the composition/temperature driven phase transitions were discussed, and the temperature−electric field (T − E) phase diagram was accordance with actual phase diagram based on the experimental data.