La/Mn Codoped AgNbO 3 Lead-Free Antiferroelectric Ceramics with Large Energy Density and Power Density

Dielectric materials with high energy density have attracted much attention due to their potential applications in modern electronics and electrical power systems. In this work, a large energy storage density of 3.2 J/cm 3 was achieved in La/Mn codoped AgNbO 3 antiferroelectric ceramics through enhancing the ferroelectric-antiferroelectric backward transition field and reducing the remnant polarization simultaneously. Moreover, the coexistence of Mn 2+ /Mn 3+ at A-site disrupts the randomly disordered Nb 5+ at high temperature, leading to the disappearance of freezing temperature T f . This results in a stable antiferroelectric phase M 2 over a broad temperature and thus a good temperature stability of energy density was achieved. Furthermore, the pulse discharge performance of AgNbO 3 -based ceramics was evaluated for the first time and a maximum power density of 390 MW/cm 3 was obtained in Mn-doped Ag 0.97 La 0.01 NbO 3 ceramics, which is about 8 times larger than the previously reported maximum value (50 MW/cm 3 ). These results reveal Mn-doped Ag 0.97 La 0.01 NbO 3 ceramics as a good candidate for lead-free high power capacitors.