在LaNiO_3-Pt复合电极上Pb(Zr,Ti)O_3铁电薄膜及其成分梯度薄膜的制备和研究

Preparation and Study on Pb(Zr,Ti)O_3 Ferroelectric Thin Films and Compositionally Graded Thin Films on LaNiO_3-Pt Composite Electrode

LaNiO3 (LNO) thin films were prepared on Pt(111) / Ti / SiO2 / Si substrate by metal-organic decomposition (MOD) method. Pb(Zr,Ti)O3 ferroelectric thin films and their compositionally graded thin films were prepared on LNO / Pt / Ti / SiO2 /Si substrates by Sol-gel method. The composition depth profile of a typical up-graded film was determined by using a combination of Auger Electron Spectroscopy (ASE) and Ar Ion Etching. The results confirm that the processing method produces graded composition changes. XRD analysis showed that the graded thin films possessed composite structure of tetragonal and rhombohedral. The dielectric constants of Up-graded and Down-graded thin films were higher than that of each thin film unit. The dielectric constants were 277 and 269 at 10 kHz, respectively. The loss tangents were 0.019 and 0.018 at 10 kHz, respectively. The Hysteresis loops showed that the remanent polarizations of graded thin films were higher than that of each thin film unit, but the coercive fields were smaller. The remanent polarizations of Up-graded and Down-graded thin films were 30.06 and 26.96 μC·cm-2, respectively. The coercive fields were 54.14, 54.23 kV·cm-1, respectively. The pyroelectric coefficients of Up-graded and Down-graded thin films were 4.62, 2.51×10-8 C·cm-2·K-1 at room temperature, respectively. They were higher than that of each thin film unit.

LaNiO3 (LNO) thin films were prepared on Pt(111)/Ti/SiO2/Si substrate by metal-organic decomposition (MOD) method. Pb(Zr,Ti)O-3 ferroelectric thin films and their compositionally graded thin films were prepared on LNO/Pt/Ti/SiO2/Si substrates by Sol-gel method. The composition depth profile of a typical up-graded film was determined by using a combination of Auger Electron Spectroscopy (ASE) and Ar Ion Etching. The results confirm that the processing method produces graded composition changes. XRD analysis showed that the graded thin films possessed composite structure of tetragonal and rhombohedral. The dielectric constants of Up-graded and Down-graded thin films were higher than that of each thin film unit. The dielectric constants were 277 and 269 at 10 kHz, respeetively. The loss tangents were 0.019 and 0.018 at 10 kHz, respectively. The Hysteresis loops showed that the remanent polarizations of graded thin films were higher than that of each thin film unit, but the coercive fields were smaller. The remanent polarizations of Up-graded and Down-graded thin films were 30.06 and 26.96 μ Cˆ cm(-2), respectively. The coercive fields were 54.14, 54.23 kVˆ cm(-)1, respectively. The pyroelectric coefficients of Up-graded and Down-graded thin films were 4.62, 2.51 x 10(-8) Cˆ cm(-2)ˆ K-1 at room temperature, respectively. They were higher than that of each thin film unit.