XPS, dielectric, and ferroelectric studies of the Pr0.1Ag0.9NbO3−δ lead-free perovskite structure containing defects

In this work, Pr0.1Ag0.9NbO3−δ lead-free perovskite sample was successfully prepared by solid-state method. The sample obtained was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Raman spectroscopy techniques. XRD pattern revealed that the sample crystallized in orthorhombic (Pbcm) perovskite structure with small impurities. The chemical states of elements (Pr3+, Pr4+, Ag1+, Ag0, Nb5+, Nb4+, Nb4+, and O2− states) and oxygen vacancies (δ) in Pr0.1Ag0.9NbO3−δ sample were investigated by X-ray photoelectron spectroscopy (XPS). Dielectric constant (εr) of Pr0.1Ag0.9NbO3−δ sample exhibited four dielectric anomalies at 355, 505, 565 and 631 K which are accompanying M1↔M2, M2↔M3, M3↔O, and O↔T phase transitions, respectively, which confirmed by thermogravimetric analyses (TGA). The polarization − electric field (P-E) hysteresis loops of Pr0.1Ag0.9NbO3−δ perovskite exhibited weak ferroelectric behavior at room temperature. High values of recoverable energy density (Wrec =7.80 J/cm3), and energy storage efficiency (ɳ=48.68%) were achieved at 40 kV/cm for the Pr0.1Ag0.9NbO3−δ perovskite sample. These results indicated that the Pr0.1Ag0.9NbO3−δ perovskite can be used as good lead-free candidate material for dielectric and energy storage applications.