Study the dielectric and energy storage properties of the La0.1Ag0.9NbO3−δ ceramic containing metallic Ag

In this work, La 0.1 Ag 0.9 NbO 3−δ lead-free ceramic was synthesized by the conventional solid-state method. Rietveld refinement of XRD data revealed that the La 0.1 Ag 0.9 NbO 3−δ ceramic crystallized in orthorhombic (Pbcm) structure with small impurities of metallic Ag and confirmed by TEM and XPS techniques. HR-TEM image and SAED pattern confirmed the polycrystalline nature of La 0.1 Ag 0.9 NbO 3−δ ceramic. FTIR spectrum of this ceramic revealed the formation of NbO 6 octahedral structure. Raman spectroscopy of this ceramic revealed the suppression of the ferroelectric distortion compared with pure of AgNbO 3 . The chemical elements, oxygen vacancies (δ), and electronic states of this ceramic were identified by XPS. The La 0.1 Ag 0.9 NbO 3−δ ceramic displayed the direct and indirect band gap energies of 3.75 and 1.95 eV, respectively. The dielectric constant (ε r ) of this ceramic showed four dielectric anomalies at 355, 505, 565 and 631 K which are accompanying the phase transitions (M1↔M2, M2↔M3, M3↔O, and O↔T) and confirmed by differential scanning calorimetry (DSC) technique. The P-E loops of this ceramic exhibited weak ferroelectric behavior. Significant improvement of recoverable energy density (W rec =0.450 J/cm 3 ), and energy storage efficiency (ɳ=29.05%) were achieved at 3 kV/cm for this ceramic.