Effective doping control in Sm-doped BiFeO₃ thin films via deposition temperature

Sm-doped BiFeO₃ (Bi_0.85Sm_0.15FeO₃, or BSFO) thin films were fabricated on (001) SrTiO₃(STO) substrates by pulsed laser deposition (PLD) over a range of deposition temperatures (600 °C, 640 °C and 670 °C). Detailed analysis of their microstructure via X-ray diffraction (XRD) and transmission electron microscopy (TEM) shows the deposition temperature dependence of ferroelectric (FE) and antiferroelectric (AFE) phase formation in BSFO. The Sm dopants are clearly detected by high-resolution scanning transmission electron microscopy (HR-STEM) and prove effective in controlling the ferroelectric properties of BSFO. The BSFO (T _dep = 670 °C) presents larger remnant polarization (Pr) than the other two BSFO (T _dep = 600 °C, 640 °C) and pure BiFeO₃ (BFO) thin films. This study paves a simple way for enhancing the ferroelectric properties of BSFO via deposition temperature and further promoting BFO practical applications.