Enhanced ferroelectric properties in BiAlO3 modified lead-free Mn-doped Bi0.5(Na0.8K0.2)0.5TiO3 thin films

Mn-doped (1- x )Bi 0.5 (Na 0.8 K 0.2 ) 0.5 TiO 3 - x BiAlO 3 (Mn:BNKT- x BA) thin films were synthesized on lanthanum nickelate-coated silicon substrates by sol-gel method. The second phase issue of the film can be effectively addressed by optimizing the substrate, and the maximum polarization and breakdown strength can be increased by introducing the proper amount of Al 3+ , which is advantageous for the film for energy storage. The results have shown that the Mn:BNKT-0.03BA film exhibits superior ferroelectric properties (with remanent polarization (P r ) of 23.72 µC/cm 2 , maximum polarization (P max ) of 75.37 µC/cm 2 ), which could be an excellent candidate for ferroelectric thin film capacitors.