Orientation dependent ferroelectric properties in samarium doped bismuth titanate thin films grown by the pulsed-laser-ablation method

摘要

Samarium doped bismuth titanate thin films with the composition of Bi_(3.25)Sm_(0.75)Ti_3O_(12) and with strong preferred orientations along the c axis and the (117) direction were fabricated on Pt/TiO_2/SiO_2/Si substrate by pulsed laser ablation. Measurements on Pt/BSmT/Pt capacitors showed that the c-axis oriented film had a small remanent polarization (2P_r) of 5 μC/cm~2, while the highly (117) oriented film showed a 2P_r value of 54 μC/cm~2 at an electrical field of 268 kV/cm and a coercive field E_c of 89 kV/cm. This is different from the sol-gel derived c-axis oriented Bi_(3.15)Sm_(0.85)Ti_3O_(12) film showing a 2P_r value of 49 μC/cm~2.