Electrical and magnetic properties of Mn-doped 0.7BiFeO3–0.3PbTiO3 thin films prepared under various heating atmospheres

Multiferroic Mn-doped 0.7BiFeO3–0.3PbTiO3 thin films were fabricated on Pt/TiOx/SiO2/Si substrates by chemical solution deposition. Perovskite single-phase thin films were fabricated by varying the heating atmosphere using gases such as N2, O2 and O3/O2. Typical ferroelectric polarization (P)–electric field (E) and ferromagnetic magnetization (M)–magnetic field (H) hysteresis loops were observed for the synthesized thin films. The electrical and magnetic properties of the Mn-doped 0.7BiFeO3–0.3PbTiO3 thin films were influenced by the heating atmosphere during crystallization. Among these thin films, 5 mol% Mn-doped 0.7BiFeO3–0.3PbTiO3 thin films, which were crystallized in O2, exhibited good surface morphologies and ferroelectric properties with remanent polarization (Pr) of approximately 40 μC cm−2 and a coercive field (Ec) of 100 kV cm−1 at room temperature. On the other hand, films crystallized in N2 and O3/O2 atmospheres had larger root-mean-square roughness values and leakage current at room temperature. These facts are considered to be related to the defect structure in the resultant thin films.