Optical and Ferroelectric Properties of $${\hbox {Bi}}_{0.95}{\hbox {Gd}}_{0.05}{\hbox {Fe}}_{1-x}{\hbox {Cr}}_{x}{\hbox {O}}_{3}$$

Abstract

In this paper, optical and ferroelectric properties were investigated for gadolinium, $${\hbox {Gd}}^{3+}$$ (5 at.%) and chromium, $${\hbox {Cr}}^{3+}$$ (0–8 at.%) co-doped of BiFeO $$_3$$ . Chemical solution deposition (CSD) method was employed as compatible device fabrication technology to synthesize Gd and Cr co-doped multiferroic $${\hbox {BiFeO}}_{3}$$ $$({\hbox {Bi}}_{0.95}{\hbox {Gd}}_{0.05}{\hbox {Fe}}_{1-x}{\hbox {Cr}}_{x}{\hbox {O}}_{3}$$ with $${\hbox {x}}$$ = 0–0.08). X-ray diffraction (XRD) analysis confirmed a well-defined crystalline phase with a tendency towards structural change from rhombohedral to orthorhombic symmetry. Crystallite size was found to reduce substantially from 34 to 13.5 nm with increasing the doping concentration of $${\hbox {Cr}}^{3+}$$ . The field emission scanning electron microscopy (FESEM) demonstrated a significant reduction in grain size of doped $${\hbox {BiFeO}}_{3}$$ compared to un-doped one following the trend obtained from XRD results. Ferroelectric nature of samples was obtained from polarization versus electric field measurements. Improved ferroelectric order was displayed in co-doped $${\hbox {BiFeO}}_{3}$$ with a maximum remnant polarization of 0.23 μ $${\hbox {C}}/{\hbox {cm}}^2$$ . Diffuse reflectance measurement by UV–Vis–NIR spectroscopy of Gd $$^{3+}$$ and $${\hbox {Cr}}^{3+}$$ co-doped $${\hbox {BiFeO}}_{3}$$ has shown a significant reduction in the optical band-gap energy $$({\hbox {E}}_{g})$$ to 1.71 eV compared to 2.03 eV of pure BiFeO $$_{3}$$ counterpart.