柔性云母基底上的Ba_(0.77)Sr_(0.23)TiO_(3)铁电薄膜的制备与研究

Preparation and property of Ba_(0.77)Sr_(0.23)TiO_(3)ferroelectric thin films on flexible mica substrate

利用脉冲激光沉积系统(Pulsed Laser Deposition,PLD)在柔性云母基底上制备了Ba_(0.77)Sr_(0.23)TiO_(3)(BST)铁电薄膜,并研究了薄膜的微观结构与电学性能。结果表明,所制备的BST薄膜呈现出(111)取向的单晶结构,表面粗糙度仅为1.96 nm。BST铁电薄膜表现出良好的铁电性能,剩余极化值(2Pr)为6.46μC/cm^(2),最大极化值(2P_(max))为17.8μC/cm^(2),在经历1011次双极性开关循环后,仍能保持良好的铁电性能。对BST薄膜的I-V曲线进行线性拟合分析,揭示其电流转换机制为从低场强下的欧姆导电机制转变为高场强下的空间电荷限制电流效应(Space-Charge-Limited Current,SCLC)。这些结果可为柔性非易失性存储器件的研究提供一些新的思路。

A method of preparing Ba_(0.77)Sr_(0.23)TiO_(3)(BST)ferroelectric thin film on the flexible mica substrate by pulsed laser deposition(PLD)was introduced,and the microstructure and electrical properties of thin film were investigated.It was found that the prepared flexible BST films exhibited a single-crystal structure with(111)orientation and average roughness of only 1.96 nm.The residual polarization(2P_(r))and maximum polarization(2P_(max))were tested as 6.46μC/cm^(2)and 17.8μC/cm^(2),respectively,demonstrating excellent ferroelectric property.After 1011 bipolar switching cycles,the BST film still exhibited good ferroelectric properties.Subsequently,the linear fitting analysis of the I-V curves were carried out and the conduction mechanism of BST film was revealed.As the electric field strength increased,the conduction mechanism changed from the ohmic contact mechanism to the space charge limited current(SCLC)effect mechanism.This study can provide a new way to prepare flexible nonvolatile storage devices.