Improved multiferroic properties of graded Mn doped BiFeO3 thin film

The compositionally graded BiFe1-XMnXO3 (0.0 ≤ x ≤ 0.3) thin film was deposited on LaNiO3 coated Si (100) substrate via pulsed laser deposition technique to investigate multiferroic properties. This thin film had a (l00) oriented perovskite structure without any secondary phases. Compared with the pure BiFeO3 film, the graded film not only exhibits out of plane magnetic anisotropy but also increases ferroelectric polarization and dielectric tunability. A large remanent polarization of Pr∼69.47 μC/cm2 and coercive field of HC∼86.95 kV/cm are observed in such a graded thin film. These improved responses could be due to spontaneous and induced polarization of individual layers. Moreover, electrostatic coupling, polarization gradient and elastic integration between layers also contributed for the enhancement of multiferroic properties in graded thin film. This work presents a feasible way to design a new kind of electronic devices based on graded multiferroic for developing high power and energy density applications.