LaNiO3衬底上Pb(ZrxTi1－x)O3铁电薄膜及梯度薄膜的制备和研究

报道了在镍酸镧 (LaNiO₃, 简称LNO)衬底上锆钛酸铅 Pb(Zr_xTi_1－x)O₃, 简称PZT]铁电薄膜及其成分梯度薄膜的结构、介电性能、铁电性能以及热释电性能. 首先通过金属有机化合物热分解(MOD)法在Si(100)基片上制备出LaNiO₃, 薄膜, 再通过溶胶-凝胶(sol-gel)法, 在LNO/Si(100)衬底上制备出Pb(Zr_0.80Ti_0.20)O₃, PZT(80/20)]和Pb(Zr_0.20Ti_0.80)O₃, PZT(20/80)]铁电薄膜及其成分梯度薄膜. 经俄歇微探针能谱仪(AES)对制备的梯度薄膜进行了成分深度分析, 结果证实成分梯度的存在. 经XRD分析表明, 制备的梯度薄膜为四方结构和三方结构的复合结构, 但其晶面存在一定的结构畸变. 经介电频谱测试表明, 梯度薄膜的介电常数比每个单元的介电常数要大, 但介电损耗相近. 在10 kHz下, 梯度薄膜的介电常数和介电损耗分别为317和0.057. 经电滞回线的测试表明, 梯度薄膜的剩余极化强度比每个单元都大, 而矫顽场却明显较小. 梯度薄膜的剩余极化强度和矫顽场分别为29.96 μC?cm^-2 和54.12 kV?cm^－1. 经热释电性能测试表明, 室温下梯度薄膜的热释电系数为5.54×10-8 C?cm^－2?K^－1, 高于每个单元的热释电系数.

Preparation and Study on Pb(ZrxTi1-x)O3 Ferroelectric Thin Films and Compositionally Graded Thin Films on LaNiO3/Si Substrates

The structural, dielectric, ferroelectric and pyroelectric, properties of Pb(Zr_xTi_1－x)O₃ (PZT) ferroelectric thin films and their compositionally graded thin films on LaNiO₃/Si substrates were reported. Firstly, LaNiO₃ (LNO) thin films were prepared on Si(100) wafer by metalorganic decomposition (MOD) method. Then, Pb(Zr_xTi_1－x)O₃ ferroelectric thin films and their compositionally graded thin films were prepared on LaNiO₃/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 and Ar ion etching. The results confirm that the processing method produces graded composition change. XRD analysis shows that the graded thin films possess composite structure of tetragonal and rhombohedral. The dielectric constant of the graded thin films is higher than that of single-phase thin film, but dissipation factor is similar with each other at 10 kHz. The dielectric constants and dissipation factor for graded thin film annealed at 600 °C for 0.5 h are found to be 317 and 0.057 at 10 kHz, respectively. The hysteresis loops show that the remanent polarization of graded thin film is higher than that of single-phase thin film, but the coercive field is smaller than them. The remnant polarization (Pr) and coercive field (Ec) of the graded film are estimated to be 29.96 μC?cm^－2 and 54.12 kV?cm^－1, respectively. The pyroelectric coefficient of the graded thin film, which is 5.54×10^-8 C?cm^－2?K^－1 at room temperature, shows gradual increase with the temperature and is higher than that of single-phase thin film.