沉积氧压对Bi_(1.5)ZnNb_(1.5)O_7薄膜的结构和介电特性的影响

Influence of Deposition Oxygen Pressure on Structure and Dielectric Properties of Bi_(1.5)ZnNb_(1.5)O_7 Thin Films

采用固相反应法合成具有焦绿石立方结构的Bi1.5ZnNb1.5O7(BZN)陶瓷靶材,采用脉冲激光沉积法在Pt/SiO2/Si(100)基片上制备立方BZN薄膜。研究了沉积氧压的变化对薄膜的结晶性能,微观形貌以及介电性能的影响。结果表明:沉积的BZN薄膜都呈现出立方焦绿石单相结构,但是薄膜的取向随氧压变化而变化。当沉积氧压为10 Pa时,薄膜的(222)晶面拥有最强的择优取向。随着氧压的升高,BZN薄膜的介电常数明显降低。在10 Pa氧压下沉积的BZN薄膜展示出介电可调特性为5%(500 kV/cm)。

Bi1.5ZnNb1.5O7（BZN） ceramic targets were prepared by solid-state reaction technology.BZN thin films were prepared on Pt/SiO2/Si（100） substrates by pulsed laser deposition under different oxygen pressure.The effects of deposition oxygen pressure on microstructure and dielectric properties of BZN thin films also were discussed.The results indicated that the deposited BZN thin films have a pure cubic pyrochlore structure.However,the preferential orientation of BZN films alters with oxygen pressure.Under the oxygen pressure of 10 Pa,thin film shows the strongest preferential orientation of（222） plane.As the oxygen pressure increasing,dielectric constant of thin film decreased significantly.BZN thin films deposited on the 10 Pa oxygen pressure have the maximum tunability of 5% at 500 kV/cm.