Study of the solubility of La3+–Dy3+ defect complexes and dielectric properties of (Ba1−xLax)(Ti1−xDyx)O3 ceramics
| Autor: | Da-Yong Lu, Shu-Zhen Cui, Xiu-Yun Sun |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Permittivity
Materials science Scanning electron microscope Process Chemistry and Technology Dielectric Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Ion symbols.namesake Crystallography law Materials Chemistry Ceramics and Composites symbols Dielectric loss Solubility Raman spectroscopy Electron paramagnetic resonance |
| Zdroj: | Ceramics International. 41:2301-2308 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2014.10.035 |
| Popis: | Based on the double-site compensation mode, the solubility of La Ba • – Dy Ti ′ defect complexes and the dielectric properties of (Ba 1− x La x )(Ti 1− x Dy x )O 3 (0.03≤ x ≤0.20) ceramics (BLTD) were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, electron paramagnetic resonance (EPR), and dielectric measurements. The solid solubility of La Ba • – Dy Ti ′ defect complexes in the BaTiO 3 lattice was determined to be x =0.17. With an increase in x , the increase in the unit cell volume was linear and satisfied Vegard׳s law. The dielectric-peak temperature ( T m ) decreased rapidly at a rate of −23 °C/at% La Ba • – Dy Ti ′ . The BLTD ceramics with x =0.05 and 0.07 met the Y5V specification with a higher room-temperature permittivity ( e RT ′ ~4000 and ~3000) and a lower dielectric loss (tan δ g =2.004 EPR signal associated with ionized Ti-vacancy defects appeared in all of the BLTD ceramics. The exclusive occupations of La 3+ ions at Ba sites and the preference for the self-compensation mode by Dy 3+ ions are responsible for the formation of predominant La Ba • – Dy Ti ′ defect complexes and the appearance of the minute concentration of Ti vacancies and Dy Ba • – Dy Ti ′ defect complexes. |
| Databáze: | OpenAIRE |
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