Structure and Dielectric Behavior of Yb2O3-MgO Co-Doped 0.92BaTiO3-0.08(Na0.5Bi0.5)TiO3 Ferroelectric Relaxor.

ABSTRACT: Dielectric properties and structure of 0.015Yb2O3-xMgO doped 0.92BaTiO3-0.08(Na0.5Bi0.5)TiO3 ceramics with x = 0.0-0.025 have been investigated. As Yb2O3-MgO was added into the BT-NBT, the phase changes from tetragonal to pseudo-cubic, with the tetragonality c/a decreases from 1.011 to 1.008 and XRD peaks broadened. The combined study of XRD and TEM image revealed a formation of core-shell structure in grains with core of 400-600 nm and the shell of a thickness 60-200 nm. There is a slowly phase transition against temperature from the variable temperature Raman analysis. The ferroelectric relaxor peak of BT-NBT decreases from ~4000 to ~2000 and a new broad dielectric peak with an equivalent maximum (εr'~2300) appears in the temperature dependent dielectric constant curve (εr'-T), which produces a flat εr'-T curve. Sample 0.92BaTiO3-0.08(Na0.5Bi0.5)TiO3-0.015Yb2O3-0.005 MgO and 0.92BaTiO3-0.08(Na0.5Bi0.5)TiO3-0.015Yb2O3-0.01MgO give a εr' variation within ±14% and ±10% in 20-165 °C. The core-shell microstructure should take account for the flattened εr'-T behavior of these samples.

SUBMITTER: Ren XH 

PROVIDER: S-EPMC8618925 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature