Ferroelectric devices are widely applied in many fields, such as energy conversion and communication. The aging effect in ferroelectric materials plays a central role in the reliability of the related equipments. But ...Ferroelectric devices are widely applied in many fields, such as energy conversion and communication. The aging effect in ferroelectric materials plays a central role in the reliability of the related equipments. But it is very difficult to understand the origin of aging effect in ferroelectrics because these materials possess different defects and exhibit various aging behavior. The reverse transition temperature in lead titanate doped with lanthanum increases during aging at ferroelectric phase was reported. It is well known that lattice defects, such as vacancies and solute atoms, are ubiquitous in crystalline solids. These point defects affect physical properties in ferroelectrics significantly. The abnormal increase of the reverse transition temperature was discussed in terms of diffusion of point defects during aging. Dielectric performance in the material after aging was measured and discussed as well.展开更多
Ability of epitaxial perovskite oxide ferroelectric films to maintain a poled polarization state on a long-term scale is crucial for advanced devices employing such films.Here polarization relaxation with time,or agin...Ability of epitaxial perovskite oxide ferroelectric films to maintain a poled polarization state on a long-term scale is crucial for advanced devices employing such films.Here polarization relaxation with time,or aging,is experimentally studied in epitaxial capacitor heterostructures of PbTiO3 sandwiched between SrRuO_(3)and Pt electrodes.The relaxation obeys logarithmic time-decay for the time 10^(2)–10^(5)s after poling pulses.The decay is by factor10 slower than that reported for polycrystalline films.Our experimental results show that existing models are insufficient for epitaxial films.展开更多
基金Project supported by Shanghai Pujiang Project (05PJ14082)Shanghai Shuguang Project (04SG48)
文摘Ferroelectric devices are widely applied in many fields, such as energy conversion and communication. The aging effect in ferroelectric materials plays a central role in the reliability of the related equipments. But it is very difficult to understand the origin of aging effect in ferroelectrics because these materials possess different defects and exhibit various aging behavior. The reverse transition temperature in lead titanate doped with lanthanum increases during aging at ferroelectric phase was reported. It is well known that lattice defects, such as vacancies and solute atoms, are ubiquitous in crystalline solids. These point defects affect physical properties in ferroelectrics significantly. The abnormal increase of the reverse transition temperature was discussed in terms of diffusion of point defects during aging. Dielectric performance in the material after aging was measured and discussed as well.
基金the Finnish Funding Agency for Innovation(Grant No.400.31.2013).
文摘Ability of epitaxial perovskite oxide ferroelectric films to maintain a poled polarization state on a long-term scale is crucial for advanced devices employing such films.Here polarization relaxation with time,or aging,is experimentally studied in epitaxial capacitor heterostructures of PbTiO3 sandwiched between SrRuO_(3)and Pt electrodes.The relaxation obeys logarithmic time-decay for the time 10^(2)–10^(5)s after poling pulses.The decay is by factor10 slower than that reported for polycrystalline films.Our experimental results show that existing models are insufficient for epitaxial films.
