Defect engineering for control of polarization fatigue in Bi3.25La0.75Ti3O12 thin film capacitors

Cerium-doped Bi3.25La0.75Ti3O12 (BLT) thin films were formed by depositing sol-gel solutions on Pt/Ti/SiO2/Si (100) structures. Partial replacement of La3+ by Ce3+ modified the lattice ordering but maintained bismuth-layered structure. The Ce4+ doping in BLT up to 5% of Ti atoms did not affect the single phase bismuth-layered structure but small modification was observed in structural orientation, which influenced the microstructure and ferroelectric properties of BLT films. Partial replacement of La3+ by Ce3+ decreased the remanent polarization but small (about 1% of Ti atoms) Ce4+ substitution enhanced the remanent polarization by about 20% in BLT films as well as it showed fatigueless response up to 10(10) switching cycles. The control of oxygen vacancies (defect engineering) influences the ferroelectric fatigue in the BLT films dramatically.