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We prepared Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) thin films with a (111)-preferred orientation on Pt/Ti/SiO 2 /Si substrates by a sol–gel method, and investigated the effects of heating rates on the crystallization process and kinetics by X-ray diffraction, transmission electron microscopy and Avrami׳s model. We found that the (111)-orientated initial crystallites directly formed on the top of Pt in the early stage of crystallization, and had smaller lattice parameters and an enhanced Ti content than the standard perovskite PZT. The quantity and distribution of the initial crystallites were dependent on the heating rates. The initial crystallite acted as a nucleation site for the perovskite PZT, which grew with a columnar grain structure into the pyrochlore matrix throughout the film. Using Avrami׳s model, we found that the effective activation energy for crystallization of the PZT films heated at a fast heating rate of 35 °C/s to be 241 kJ/mol, much lower than 325 kJ/mol for crystallization of the PZT films heated at a low heating rate of 25 °C/min. These results show that a fast heating rate in annealing process can reduce the effective activation energy for crystallization, improve the microstructure including the crystalline orientation, grain size and shape and thus the electrical properties of PZT thin films. [ABSTRACT FROM AUTHOR]

Abstract: In the present work, Ferroelectric Lead zirconate titanate [Pb(ZrxTi1-x)O3: PZT] films with a nominal formula Pb1.1(Zr0.52Ti0.48)O3 were prepared with the sol–gel method and post-annealed by rapid thermal annealing. Different heating rates were adopted to explore their effect on microstructure and electrical properties of PZT films. The results show that heating rate has a significant effect on the orientation and grain size distribution of PZT films under the same annealing temperature, which further results in different dielectric and ferroelectric properties. It is found that the faster heating rate is not favorable for enhancing the ferroelectricity of PZT films although it promotes the phase transition process. The relationship between heating rate and microstructure of PZT films is discussed based on its effect on the nucleation and growth process of PZT perovskite phase. It is proposed that the nucleation and growth process of perovskite phase occurs under different stress states at different heating rates, which leads to the varying orientations of films. [Copyright &y& Elsevier]

Abstract: In the present work, lanthanum nickel oxide (LaNiO3, LNO) films were prepared by the sol–gel method. Microwave processing in separated microwave magnetic field (H field) was introduced during pyrolysis and annealing treatments. The heating behavior of LNO films in microwave H field was explored. The effects of microwave processing on the orientation and microstructure of LNO films were investigated compared to those obtained from conventional furnace processing. The results show that the (100)-oriented LNO films can be prepared through microwave processing at pyrolysis stage and annealing stage, even though the film thickness obtained from a single coating is much larger than the grain size. On the contrary, (110)-orientation predominates in the films prepared through conventional furnace processing. Furthermore, microwave annealing is favorable for improving the crystallinity of LNO films and promoting the transition of the transport property from the insulating-type to the metallic-type. The underlying mechanism of the above-mentioned effects is discussed in terms of the heating behavior of amorphous and crystallized LNO films prepared in microwave field. [Copyright &y& Elsevier]