Synthesis, structural characterization and ferroelectric properties of Pb0.76Ca0.24TiO3 nanotubes

A capillary-enforced template-based method has been applied to fabricate Pb0.76Ca0.24TiO3 (PCT24) nanotubes via filling PCT24 precursor solution, prepared by modified sol–gel method, into nanochannels of anodic aluminum oxide templates. The morphology and structure of as-prepared PCT24 were examined by scanning electron microscopy, transmission electron microscopy (TEM) and X-ray diffraction techniques. The obtained PCT24 nanotubes with diameter of ∼200 nm and wall thickness of ∼20 nm exhibited a tetragonal perovskite structure. High resolution TEM (HRTEM) analysis confirmed that as-obtained PCT24 nanotubes made up of nanoparticles (5–8 nm) which were randomly aligned in the nanotubes. Formation of some solid crystalline PCT24 nanorods, Y-junctions and multi-branches were observed. Interconnections in the pores of template are responsible for the growth of Y-junctions and multi-branches. The possible formation mechanism of PCT24 nanotubes/nanorods was discussed. Ferroelectric hysteresis loops of PCT24 nanotube arrays were measured, showing a room temperature ferroelectric characteristic of as-prepared PCT24 nanotubes.