Physical properties of new,lead free (Na0.5Bi0.5)(1−x)BaxTi(1−x)(Fe0.5Nb0.5)xO3 ceramics |
| |
Authors: | A Amouri J Rouquette B Hehlen JL Sauvajol H Khemakhem |
| |
Affiliation: | 1. Laboratoire de Physique Mathématiques et Application-Unité des Matériaux Ferroélectriques-Faculté des Sciences de Sfax, Route Soukra Km 3, 5, B.P. 1171, 3000 Sfax, Tunisia;2. Le laboratoire des Colloïdes, Verre, et Nanomatériaux: UMR CNRS 5587, Unité mixte de recherche 5587-CNRS-UM2-Université Montpellier 2, F-34095 Montpellier, France;3. Institut Charles Grehardt, UMR CNRS 5253, Equipe PMOF, Universtiy of Montpellier 2, F-34095 Montpellier, France |
| |
Abstract: | This study reports on the synthesis of polycrystalline samples of (Na0.5Bi0.5)(1−x)BaxTi(1−x)(Fe0.5Nb0.5)xO3 with x=0, 0.025, 0.05, 0.075, and 0.1, using the solid-state reaction technique. It investigates the effects of the substitution of sodium and bismuth by barium in the A site and of titanium by iron and niobium in the B site with regard to the free NBT symmetry and dielectric properties were investigated. The crystallographic and dielectric properties were also investigated. The diffractograms showed that all the samples had a single phase character. The increase of ceramic lattice parameters induced an increase in the size of the perovskite lattice. This increase was caused by the increase of the radii of the A and B sites. Room temperature X-ray data revealed that the ceramic structures underwent a gradual distortion with the increase in the composition fraction. Dielectric permittivity was measured in the temperature range of 120–780 K with frequencies ranging from 1 to 103 KHz. Three anomalies, namely Td, T1 and Tm, were detected and noted to coexist at lower Td and Tm as the rate of substitutions increased. All the samples exhibited a diffuse phase transition and implied better dielectric permittivity maxima values at temperatures approaching room temperature, since the substitution rate values increased more than that of pure NBT. A relaxor behavior with ΔTm=14 K and ε'rmax=3876 at 1 kHz was observed for (Na0.5Bi0.5)0.9Ba0.1Ti0.9(Fe0.5Nb0.5)0.1O3 ceramic. |
| |
Keywords: | C Dielectric properties Lead free ceramics Solid-state reaction X-ray diffraction |
本文献已被 ScienceDirect 等数据库收录! |
|