Effect of TiO_2 Seeding Layer on Crystalline Orientation and Ferroelectric Properties of Bi_(3.15)Nd_(0.85)Ti_3O_(12) Thin Films

Bi_(3.15)Nd_(0.85)Ti_3O_(12)(BNT)thin films with and without a TiO_2 seeding layer were fabricated on Pt/Ti/SiO_2/Si substrates by sol-gel method at 750℃.The effect of seeding layer on structural and electrical properties of BNT thin films was investigated.X-ray diffraction pattern shows that the BNT thin film deposited directly on Pt/Ti/SiO_2/Si substrate exhibits predominantly(117)and(001) orientation while the BNT thin film grow on Pt/Ti/SiO_2/Si substrate with a TiO_2 seeding layer show a highly a axis orientation with the(200)strongest peak.The BNT thin film with a TiO_2 seeding layer is a more dense and homogeneous than that deposite directly on Pt/Ti/SiO_2/Si substrate.The P_r and E_c values of BNT films with and without WiO_2 layer are 43.6 and 26μC/cm~2,and 91 and 80.5kV/cm, respectively.The fatigue test exhibits a very strong fatigue endurance up to 10~9 cycles for both films. The addition of TiO_2 seeding layer does not decrease the fatigue characteristic of BNT thin film.The leakage current density are generally in the order of 10~(-6)-10~(-5)A/cm~2 for both samples.