采用射频磁控溅射法结合高真空后退火处理,在MgO(001)单晶基片上制备了Pt薄膜。应用脉冲激光沉积法在Pt/MgO上进一步生长了Ba0.6Sr0.4TiO3(BST)薄膜。借助X射线衍射仪(XRD)、铁电测试仪、LCR表研究了BST/Pt/MgO的结构和性能。研究发现,700℃真空退火可以保证Pt薄膜在MgO基片上实现(001)高度择优生长,以(001)Pt薄膜为模板,可以进一步获得(001)高度择优取向具有铁电性能BST薄膜。在100 Hz测试频率下,BST薄膜最大介电常数为1100、调谐率为81%、品质因数为21;在7 V的电压下,漏电流密度1.85×10-5A/cm2,进一步分析表明,BST薄膜在0-2.6 V之间满足欧姆导电机制,在2.6-7 V之间满足普尔-弗兰克导电机制。
Pt film was prepared on MgO(001) single crystal substrate using radio-frequency magnetron sputtering,combined with high vacuum post annealing process.BST film was further fabricated on Pt/MgO by pulsed laser deposition method.The structure and physical properties of BST/Pt/MgO heterostrucutre were characterized by XRD,ferroelectric tester,and LCR meter.The results showed that Pt film is highly(001) oriented after 700 ℃ vacuum annealing,and(001) highly oriented BST film with ferroelectric property can be obtained using(001) Pt as template.The test frequency is 100 Hz,the maximum dielectric constant,tunability and dielectric loss of a BST capacitor are 1100,81%,0.074,respectively.The leakage current density of the BST capcitor is 1.85×10-5 A/cm2 at 7 V.Schottky conduction mechanism is found to dominate the current conduction at low voltages ranging from 0 to 2.6 V,and at the voltages,ranging from 2.6-7 V,BST capacitor meets Poole-Frenkel emission conduction.