Room temperature tunability of ferroelectricity and dielectricity in La and Mn codoped BiFeO3 nanoflakes: Implications for electronic devices applications

This study sheds a light on the in-situ growth of nanoflakes structure in Bi₀.₉La₀.₁Fe₀.₅Mn₀.₅O₃ (BLFMO) thin film. The BLFMO thin films of various thicknesses were grown on LaNiO₃ (LNO) coated Si (100) substrates using pulsed laser deposition technique. A long-range crystal structure of the as prepared BLFMO thin films was studied by X-ray diffraction measurements, which shows that the LNO buffer layer allows growth for a specific orientation. The compact and densely packed nanoflake structures in BLFMO thin film samples were confirmed by surface morphological investigations. To measure the polarization versus electric field (p-E) loop of BLFMO chip samples, a standard bipolar sinusoidal waveform with its magnitude of 250 kV/cm was applied at the frequency of 1 kHz. The maximum saturation and remnant polarizations of 104.50 μC/cm² and 86.24 μC/cm² respectively were probed for a critical thickness (420 nm) of the BLFMO layer. The voltage polarity-dependent leakage current behavior of Ag/BLFMO/LNO thin-film capacitor is thoroughly explored in detail. The value of leakage current density was observed from 1.16 × 10^?4 to 2.24 × 10^?5 J/cm² for BLFMO thin films at an external applied electric field of 300 kV/cm. The highest tunability ～60.20% and minimum temperature capacitance coefficient ～1.23 × 10^?3 were also observed for the same critical thickness of proposed chip element. The present study may open up a new opportunity to fabricate thin film based ferroelectric memory devices.