Ni掺杂对铋层状钙钛矿Bi6Fe2Ti3O18薄膜微结构及铁电性能的影响

Effect of Ni Doping on Microstructure and Ferroelectric Properties of Bismuth-layered Perovskite Bi6Fe2Ti3O18 Thin Films

利用化学溶液沉积法在Pt/Ti/SiO2/Si（100）基片上制备了Bi6Fe（2–x）NixTi3O（18）（x=0,0.5,1.0,1.5）薄膜,研究了不同Ni掺杂量对Bi6Fe2Ti3O（18）薄膜微结构和铁电性能的影响。X射线衍射和Raman光谱测试结果表明：当Ni掺杂量x=1.5时,薄膜仍能保持单相结构,晶格畸变和薄膜压应力随Ni掺杂量分别逐渐增大和减小。Ni掺杂薄膜具有Aurivillius相陶瓷材料典型的不规则扁平状颗粒。随着Ni掺杂量逐渐增加,薄膜的Ps和Pr先增大后减小,而Ec和漏电流逐渐增大。Ni掺杂导致的Bi6Fe2Ti3O（18）薄膜晶格畸变增加,薄膜压应力减小和氧空位浓度增加是引起薄膜铁电性能变化的主要原因。

Ni doped Aurivillius phase bismuth-layered perovskite Bi6Fe2Ti3O18 thin films were fabricated on Pt/Ti/SiO/Si（100） substrates via chemical solution deposition. The effect of Ni doping on the microstructure and ferroelectric properties of the films was investigated. Based on the results by X-ray diffraction and Raman spectroscopy, there is no secondary phase formed in the films when the Ni doping amount x of 1.5. The lattice distortion and internal compressive strain of the films increase and decrease with increasing the Ni doping amount. The SEM morphology images show that the Ni doped films have plate-like grains, which usually appear in the Aurivillius oxide ceramic samples. The saturation polarization and remanent polarization of the films firstly increase and then decrease, while the coercive electric field and leakage current monotonically increase with the increase of Ni doping amount. By analyzing various factors, we find that the lattice distortion and the oxygen vacancies increase, while the internal compressive strain decreases after Ni doping, indicating the ferroelectric properties of the Ni doped Bi6Fe2Ti3O18 films.