Origin of Enhanced Dielectric Tunability in Antiferroelectric Ceramic Systems

Abstract Antiferroelectric ceramics are considered as highly promising materials for the development of novel DC‐link, snubber, and filter capacitors used in high‐power and high‐speed electronics for electromotive and renewable energy applications, medical equipment, and weapons platforms. In particular, the increase of the dielectric permittivity with bias electric field, i.e., the dielectric tunability, is one of the most interesting and still not fully understood properties of antiferroelectric materials. The in situ dielectric measurements and thermometry of Pb 0.99 Nb 0.02 [(Zr 0.57 Sn 0.43 ) 0.92 Ti 0.08 ] 0.98 0 3 ceramics reveal that the dielectric response increases with bias electric field in the antiferroelectric phase due to the non‐linear contributions, most likely originating in the irreversible domain wall motions. Furthermore, extraordinarily high values of the dielectric tunability (≈375%) and the figure of merit (≈1680%) are determined at the temperature of the triple point. The minimization of the domain size near the triple point is proposed to be responsible for the enhanced dielectric tunability. The proposed mechanism is supported by the enhanced irreversible Rayleigh coefficient and via observation of minimized domains by piezoresponse force microscopy. The exploration of the role of the domain structure in antiferroelectrics contributes to a better understanding of their unique dielectric properties and opens a new possibility for the development of high‐performance capacitors.