化学计量对Ba_(1-x)Sr_xTiO_3薄膜介电性能的影响

Preparation and dielectric properties of Ba_(1-x)Sr_xTiO_3 thin films

采用脉冲激光沉积法,在Pt/Ti/SiO2/Si衬底上制备了Ba1-xSrxTiO3薄膜,通过改变Sr化学计量,研究了其介电性质.实验结果发现:随着Sr化学计量的增加,薄膜的介电系数明显增大,而损耗仍然保持在较低的水平.研究表明:薄膜介电系数的增大是由于薄膜中颗粒尺寸的减小,导致了居里温度的降低.另外,C-V特性研究发现:随着Sr化学计量的增加,薄膜的电容调谐度也有所提高.

Ba1-xSrxTiO3 thin films have been fabricated on Pt/Ti/SiO2/Si substrates by a pulscd-laser deposition method via varying the Sr constant. The dielectric constant of thin films was obviously enhanced, whose dieiectric loss was remained at a low level, with increasing Sr content. The curie temperature decreased with the increase of Sr Content, whichris the cause of the dielectric enhancement. In addition, from the C-V measure ments, the dielectric tunability increases with the increase of Sr content.