A novel high-k ‘Y5V’ barium titanate ceramics co-doped with lanthanum and cerium

摘要: Abstract Structural, dielectric, and ferroelectric properties of a novel high-k ‘Y5V’ (Ba 1− x La )(Ti /4− y Ce )O 3 ceramics (where =0.03 =0.05, denoted by BL3TC5) with the highest dielectric response ( e ′>10 000) among rare-earth-doped BaTiO to date are investigated in detail using SEM, TEM, XRD, DSC, EPR, Raman spectroscopy (RS), temperature frequency, electric field dependences permittivity e′ ), hysteresis loops. The BL3TC5 diffusion phase transition occurs around peak temperatures T m ) near room characteristic thermal relaxation. Powder XRD data defect complex model were given. “Relaxor” behavior associated an order/disorder formation solid solution discussed. EPR results provided evidence Ti vacancies as compensating for lattice defects. High-k relaxor nature is characterized average cubic structure long-range disordering local polar ordering; slow change ′ P r curves ; no observed DSC; broad, red-shifted A 1 (TO 2 phonon mode at 251 cm −1 accompanying disappearance “silent” 305 cm clear anti-resonance effect 126 cm temperature.