【摘要】 以乙醇锂和乙醇钽为起始反应物,用溶胶-凝胶法在Pt/Ti/SiO₂/Si衬底上制备了新型钽酸锂LiTa₃O₈铁电薄膜.经XRD图谱对比,该薄膜结构不同于LiTaO₃晶体结构,与正交相结构类似.SEM分析显示经过750℃结晶退火的LiTa₃O₈薄膜表面均匀平整无裂纹,膜厚约为1μm.实验结果表明,在450kV/cm时,LiTa₃O₈薄膜剩余极化强度P_r为9.3μC/cm²,矫顽场强E_c为126.8kV/cm;在9.SkV/cm时,LiTa₃O₈薄膜漏电电流为8.85×10^-9A/cm²,比LiTaO₃薄膜漏电小;在1kHz时,LiTa₃O₈薄膜介电常数为58.4,介电损耗为0.26.溶胶-凝胶法制备的LiTa₃O₈薄膜结晶温度比LiTaO₃薄膜高50℃以上.更多还原

【Abstract】 A novel ferroelectric lithium tantalate LiTa₃O₈ thin film was prepared on Pt/Ti/SiO₂/Si substrate by sol-gel method using lithium ethoxide and tantalite ethoxide as starting materials.The structure of the LiTa₃O₈ film is similar to orthorhombic,which is different from LiTaO₃ film based on XRD pattern.The SEM image reveals that the LiTa₃O₈ film crystallized at 750℃is uniform,smooth and crack-free on the surface with thickness of 1μm.The electrical experiments show that the remanent polarization P_r and coercive field E_c of the LiTa₃O₈ film polarized at 450kV/cm are 9.3μC/cm² and 126.8kV/cm,respectively;the leakage current of the LiTa₃O₈ film is 8.85×10^-9A/cm² at the electric field of 9.5kV/cm,lower than that of LiTaO₃ film.The dielectric constant and dielectric loss of the LiTa₃O₈ film are 58.4 and 0.26,respectively,at frequency of lkHz.And the crystallization temperature of sol-gel derived LiTa₃O₈ film is 50℃higher than that of LiTaO₃ film.更多还原