Structure and Dielectric Behavior of Yb₂O₃-MgO Co-Doped 0.92BaTiO₃-0.08(Na_0.5Bi_0.5)TiO₃ Ferroelectric Relaxor.

ABSTRACT: Dielectric properties and structure of 0.015Yb₂O₃-xMgO doped 0.92BaTiO₃-0.08(Na_0.5Bi_0.5)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 (ε_r'~2300) appears in the temperature dependent dielectric constant curve (ε_r'-T), which produces a flat ε_r'-T curve. Sample 0.92BaTiO₃-0.08(Na_0.5Bi_0.5)TiO₃-0.015Yb₂O₃-0.005 MgO and 0.92BaTiO₃-0.08(Na_0.5Bi_0.5)TiO₃-0.015Yb₂O₃-0.01MgO give a ε_r' variation within ±14% and ±10% in 20-165 °C. The core-shell microstructure should take account for the flattened ε_r'-T behavior of these samples.

SUBMITTER: Ren XH 

PROVIDER: S-EPMC8618925 | biostudies-literature |

REPOSITORIES: biostudies-literature