Effects of Mn substitution on ferro- and piezoelectric properties of Bi0.86Sm0.14FeO3 thin films

Research highlights: → 1 at.% Mn doping is necessary for obtaining the intrinsic properties of BSFO films. → Formation of Mn2+ is more likely based on the electronic configuration of Mn. → The negative effect of high Mn doping content on piezoresponse is more evident. - Abstract: The Bi0.86Sm0.14FeO3 (BSFO) and Bi0.86Sm0.14Fe1-xMnxO3 (BSFMO) (x = 0.01, 0.03, 0.05) thin films were deposited on indium tin oxide/glass substrates via a metal organic deposition method. 1 at.% Mn doping leads to an evident reduction of the leakage current in BSFO film. More importantly, the Bi0.86Sm0.14Fe0.99Mn0.01O3 film exhibits the lowest coercive field (Ec = 272 kV/cm), the largest remanent polarization (Pr = 53.6 μc/cm2) and the remanent out-of-plane piezoelectric coefficient (d33 = 146 pm/V). However, further increase of Mn doping content results in the deterioration of the charge retaining capability and the piezoelectric properties of the films. The negative influence of high Mn doping contents was discussed based on the structure change and the contribution of irreversible movement of non-180o domain walls in the aged films.