Enhanced dielectric temperature stability and energy-storage properties of (Y0.5Nb0.5)4+ co-doped (Bi0.5Na0.5)0.94Ba0.06TiO3 lead-free relaxor ceramics

(Bi0.5Na0.5)(0.94)Ba0.06Ti1-x(Y0.5Nb0.5)(x)O-3 (abbreviated as BNTBT-100xYN) lead-free relaxor ceramics were designed and prepared using a traditional solid-state sintering technique. The influences of the introduction of (Y0.5Nb0.5)(4+) complex ions for the dielectric properties and energy storage performances of BNTBT-100xYN ceramics were systematically studied. All samples exhibited a typical pseudo-cubic symmetry structure and obtained the dense microstructure with the uniform distribution of all elements. The ergodic relaxor behavior of all ceramics was observed and revealed a trend of increase as a function of composition. It accelerated the improvement of the temperature stability of the dielectric constant. All samples showed a single grain conduction mechanism and the activation energy decreased with the addition of composition. It is related to the generation of oxygen vacancies induced by the defect dipoles. BNTBT-6YN ceramic revealed excellent dielectric temperature stability within the temperature range from 87 to 479 degrees C and the loss tangent less than 0.05 between 25 degrees C and 474 degrees C. Besides, a high recoverable energy density of similar to 0.91 J/cm(3) with the corresponding efficiency of similar to 78.5% at applied 115 kV/cm field was achieved for BNTBT-5YN ceramic. Hence, BNTBT-5YN and BNTBT-6YN ceramics will become one of the outstanding dielectric ceramics for the electronic components.

Automated summary

The lead-free relaxor ceramics BNTBT-100xYN were designed and prepared using traditional solid-state sintering technique. The introduction of complex ions improved the temperature stability and recoverable energy density of the ceramics. The addition of composition reduced activation energy and generated oxygen vacancies, showing ergodic relaxor behavior.