Strain and morphology control over electrical behavior of pulsed laser deposited BiFeO3 films

In this communication, we report the results of the studies on thickness dependent electrical behavior of pulsed laser deposited (PLD) BiFeO3 (BFO) thin films grown on (100) single crystalline Si substrates. X-ray diffraction (XRD) measurement reveals the single phasic nature with polycrystalline growth for all the films. Atomic force microscopy (AFM) images reveal that grain size and granular morphology are highly influenced by the thickness of the films. Frequency dependent dielectric behavior at different temperatures suggests the ferroelectric nature of the films. Variation in dielectric constant with frequency, temperature and film thickness has been discussed in the context of dipole relaxation, ferroelectric nature, structural strain, granular morphology and possible oxygen vacancies in the lattice. P-E loop measurement verifies the ferroelectric nature of the films understudy and its strong dependence on the film thickness. UDR model and dipole relaxation relation were used to understand the dielectric behavior of the films understudy.