BaTiO_3/SrTiO_3多层膜的制备及其介电性质

Preparation and dielectric properties of BaTiO_3/SrTiO_3 multilayer thin films

采用脉冲激光沉积法在Pt/Ti/SiO2/Si衬底上制备了BaTiO3/SrTiO3(BTO/STO)多层膜。XRD结果表明:多层膜呈现出明显的(110)择优取向,与Ba0.5Sr0.5TiO3单层膜相比,多层膜的相对介电常数得到了明显的增强,而介电损耗仍然保持在较低的水平。室温下频率为10kHz时,BTO/STO(n=6)多层膜的相对介电常数为506,而介电损耗仅为0.033。薄膜的C V特性研究表明:多层膜呈现出较好的电容调谐度。

BaTiO3/SrTiO3 (BTO/STO) multilayer films have been fabricated on Pt/Ti/SiO2/Si substrates by a pulsed laser deposition method. From X-ray diffraction patterns, the multilayer structures have been formed, and indicating the single films are polycrystalline, while the multilayer films show a preferred orientation in (110) reflection. The dielectric constant of multilayer thin films was obviously enhanced, and the corresponding dielectric loss was remained at a low level. At a frequency of 10 kHz, a large dielectric constant of 506 was found in BTO/STO (n = 6) multilayer films at room temperature, whose dielectric loss was only 0.033. From electrical measurement, BTO/STO multilayer films show a dielectric tunability of 28.8%.