0000000000305533

AUTHOR

Sara Abou Dargham

showing 3 related works from this author

Complex structural contribution of the morphotropic phase boundary in Na0.5Bi0.5TiO3 - CaTiO3 system

2019

Abstract The correlation between structure and dielectric properties of lead-free (1-x)Na0.5Bi0.5TiO3 - xCaTiO3 ((1-x)NBT - xCT) polycrystalline ceramics was investigated systematically by X-ray diffraction, combined with impedance spectroscopy for dielectric characterizations. The system shows high miscibility in the entire composition range. A morphotropic phase boundary (MPB), at 0.09 ≤ x

010302 applied physicsDiffractionPhase boundaryMaterials scienceProcess Chemistry and TechnologyThermodynamics02 engineering and technologyDielectric021001 nanoscience & nanotechnology01 natural sciencesMiscibilitySurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsDielectric spectroscopyvisual_art0103 physical sciencesMaterials ChemistryCeramics and Compositesvisual_art.visual_art_medium[CHIM]Chemical SciencesCrystalliteCeramic0210 nano-technology
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Detection of morphotropic phase boundary in A-site/Ca-substituted Na0.5Bi0.5TiO3 complex oxides ferroelectric system

2020

Abstract Vibrational and structural properties of lead-free piezoelectric (1-x)Na0.5Bi0.5TiO3–xCaTiO3 (0 ≤ x ≤ 1.00) solid solutions have been investigated using Raman spectroscopy and X-ray diffraction. Different anomalies were detected and analyzed taking into consideration the phase transition from rhombohedral to orthorhombic phase at room temperature. All Raman bands were interpreted through the variation in the peak positions (frequency) and the corresponding half-widths at half maximum (HWHM) as a function of x. XRD used as a complementary technique to Raman spectroscopy, showed that the rhombohedral – orthorhombic phase transition went gradually through an intermediate phase consist…

DiffractionPhase boundaryPhase transitionMaterials scienceMechanical EngineeringMetals and AlloysAnalytical chemistry02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesFerroelectricity0104 chemical sciencessymbols.namesakeMechanics of MaterialsPhase (matter)Materials Chemistrysymbols[CHIM]Chemical SciencesOrthorhombic crystal system0210 nano-technologyRaman spectroscopySolid solution
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Quantification of relaxor behavior in (1 − x)Na0.5Bi0.5TiO3 – xCaTiO3 lead-free ceramics system

2019

Abstract This work examines the relaxor behavior of lead-free ceramic (1 − x)Na0.5Bi0.5TiO3–xCaTiO3 systems. A stable rhombohedral (R3c) phase is detected at room temperature for all compositions by XRD and Raman spectroscopy. Relaxor behavior was observed in the temperature range 300 K - 400 K for all materials. Ceramics exhibit normal ferroelectric properties at room temperature, and then they develop relaxor characteristics with increasing temperature showing the same dispersive properties. This work quantifies the relaxor phenomenon at low temperature. For instance, the maximum temperature of relaxor and the order of dispersion were determined at the strongest dispersion. Finally, the s…

010302 applied physicsWork (thermodynamics)Maximum temperatureMaterials scienceThermodynamics02 engineering and technologyAtmospheric temperature range021001 nanoscience & nanotechnology01 natural sciencesFerroelectricitysymbols.namesakevisual_artPhase (matter)0103 physical sciencesDispersion (optics)Materials ChemistryCeramics and Compositesvisual_art.visual_art_mediumsymbols[CHIM]Chemical SciencesCeramic0210 nano-technologyRaman spectroscopyJournal of the European Ceramic Society
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