Studying the spontaneous polarization and dielectric response of La: BiFeO3 nanocrystal (NCs)

We studied the dielectric response and ferroelectric ordering of BiFeO3 and La doped bismuth ferrite (Bi0.97La0.03FeO3) nanocrystal (NCs) synthesized through sol-gel conventional route. XRD refinement revealed the formation of rhombohedral distorted perovskite structure with negligible secondary phase. The frequency dependent dielectric constant ɛ (ɷ) showed a rapid decrease in the dielectric at low frequency (1 MHz), and become almost constant at high frequency. The surface charge and orientation polarizations are likely to be predominant governing the dielectric response. The ferroelectric measurements (P-E curve) displayed remnant polarization, which were about 0.60 μC/cm2 at 17.35 kV/cm for Bi0.97LaxFeO0.03. Our study confirmed a weak offset in the crystal structure, dielectric response and ferroelectric properties of BiFeO3 NCs as a function of La dopant ion.