Effects of Pt Buffer Layer and Sr Content on Multiferroic (Bi, Sr)FeO3 Polycrystalline Thin Films on Glass Substrates

Effects of Pt buffer layer and Sr content on the structure, surface morphology, ferroelectric, and magnetic properties of Bi
_1-x
Sr
_x
FeO
₃
(BSFO) polycrystalline films on glass substrates at reduced temperature of 450 °C have been investigated. Perovskite single phase is present in the studied BSFO films (x = 0.05-0.15) on 10-30 nm thick Pt(111) electrodes. The grain size and surface roughness of BSFO films is closely related to the morphology of Pt(111) electrodes. Further refined microstructure with reduced surface roughness is found with the increase of Sr content x. BSFO polycrystalline thin films display good ferroelectric properties with the remanent polarization (2P
_r
) of 77-103 μC/cm
²
and electrical coercive field (E
_c
) of 380-490 kV/cm. In addition, the enhanced ferromagnetic properties with magnetization (M
_s
) of 8.7-11.2 emu/cm
³
and coercivity (H
_c
) of 1211-1299 Oe are attained.