STUDY OF ELECTRICAL PROPERTIES OF DY3+ DOPED SRBI2NB2O9 AURIVILLIUS CERAMIC FOR ELECTRONIC APPLICATIONS

Abstract

The effect of Dy³⁺ substitution on the structural, dielectric and ferroelectric properties of SrBi(2-x)DyxNb2O9 (SBN) (x=0.00,0.02,0.04,0.06) was systematically investigated, and the samples were synthesized using the conventional solid-state reaction method. X-ray diffraction (XRD) confirmed the formation of a single-phase orthorhombic structure, indicating successful incorporation of Dy³⁺ into the lattice. The substitution of Dy³⁺ caused systematic variations in lattice parameters and unit cell volume, suggesting localized structural distortion. Scanning electron microscopy (SEM) revealed a plate-like grain morphology with random orientation, characteristic of layered perovskite systems. FTIR spectroscopy confirms bands are present at 816 cm-1, 612 cm-1, and 454 cm-1. Dielectric studies show well-defined ferroelectric characteristics with low dielectric loss. The dielectric constant (ɛ) was observed to be 160 for undoped SBN ceramic. The Polarization-Electric field (P-E) hysteresis measurements confirmed the ferroelectric behavior of all compositions. The remanent polarization was recorded as highest at 4% (x=0.04), and 2Pr was 7.95 µC/cm2, whereas the coercive field 2Ec was 63.05 kV/cm. The variation in remanent polarization (Pr) and coercive field (Ec) with Dy³⁺ content indicates that dopant concentration significantly influences ferroelectric characteristics. Temperature-dependent PE loops indicate a stable ferroelectric response over a wide temperature range, 30°C to 180°C, with improved polarization. Good polarization retention with minute variations in remanent polarization (Pr) and coercive field (Ec) up to 10000 switching cycles, confirming good fatigue endurance and stability. Analysis of leakage current up to 10000 switching cycles reveals good insulating behaviour of the material with reduced defects and hence exhibits good electrical stability. Overall, Dy³⁺ substitution enhances structural stability, ferroelectric switching, and dielectric properties, making them useful in energy storage and sensing applications.