Crystallization process and microstructure of sol–gel derived Pb0.9La0.1Ti0.875O3 fine fibers with a novel heat-treatment process

The Pb0.9La0.1Ti0.875O3 (PLT) fibers with fine diameters about 5 μm have been fabricated via sol–gel method. Water vapor has been applied in heat-treatment process to study its influence on the crystal-phase formation and the microstructure of PLT fibers. In contrast to that heat-treated thoroughly in air, fibers which are pretreated under water vapor flows have improved crystallization behavior and better final microstructure. The hardly decomposable ligands of triethanolamine (TEA) and the acetyl groups can be dissociated without carbonization with the help of water vapor flows at relative low temperatures. The microstructure and molecular structure are studied using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra and thermogravimetric analysis (TGA) measurements.

Graphical abstractThe Pb0.9La0.1Ti0.875O3 (PLT) fibers with fine diameters about 5 μm have been fabricated via sol–gel method. Fibers which have been pretreated under water vapor flows (see the left figure) have better continuity and surface morphology than that have not. There are many prominences in fibers which have been heat-treated thoroughly in air (see the right figure). The water vapor can make the organics, including the hardly decomposable ligands in the fibers come out directly without carbonization and remove them almost entirely under 350 °C. Therefore, the shrinkage of the surface occurs at low temperatures and does not propagate inside. In this view, the obtained PLT fibers which have been pretreated under water vapor flows exhibited excellent macro- and micro-structure.Figure optionsDownload full-size imageDownload as PowerPoint slide