高度取向的(Pb0.5Sr0.5)TiO3/LaNiO3异质结构铁电薄膜性能

高度取向的(Pb_0.5Sr_0.5)TiO₃/LaNiO₃异质结构铁电薄膜性能

摘要: 用sol-gel方法在Pt(111)/Ti/SiO₂/Si(100)衬底上制备了具有LaN iO₃(LNO)缓冲层的(Pb_0.5Sr_0.5)TiO₃(PSrT50)/LNO/Pt异质结构铁电薄膜。X射线分析发现PSrT50薄膜在(100)方向高度取向,同时扫描电镜图像显示薄膜结构致密、表面平整。通过和直接在Pt上制备的、相同厚度的PSrT50薄膜比较,PSrT50/LNO/Pt结构薄膜在室温下具有更大的剩余极化(Pr=4.5μC/cm²)和更高的介电常数(ε_r=850)。同时,漏电流机理分析表明,PSrT50/LNO/Pt结构薄膜在低电场作用下呈现Pool-Frenkel发射效应,在高电场作用下则表现为空间电荷限制电流。

Abstract: Heterostructure ferroelectric（Pb_0.5Sr_0.5）TiO₄（PSrT50）/LNO/Pt thin films have been prepared on Pt（111）/Ti/SiO₂/Si（100） substrate by sol-gel method.The X-ray diffraction indicates that the PSrT50 films exhibit highly（100） orientation and the scan electron micrography shows that the films are dense and its surface is smooth.Compared with the same-thickness PSrT50 thin film prepared directly on the Pt substrate,PSrT50/LNO/Pt heterostructure thin films show a larger remnant polarization（Pr=4.5 μC/cm²） and higher dielectric constant（ε_r=850）.Moreover,the analysis of leakage current mechanism indicate that PSrT50/LNO/Pt heterostructure thin films exist Pool-Frenkel emission at low electric field and space-charge-limited behavior at high electric field,respectively.