Sol-gel synthesis and characterization of La0.6Sr0.4CoO3 nanoparticles, nanotubes, and thin films

Nanoparticles, nanotubes and thin films of polycrystalline La0.6Sr0.4CoO3 were synthesized by the sol-gel process. DTA, AFM, SEM/EDAX and X-ray diffraction were utilized to characterize the properties of the products. The nanoparticles were obtained from the precursor sol containing metal nitrates and citric acid. The nanotubes were derived from the same sol with the aid of anodic aluminum oxide template. The thin films were prepared by spin coating the sol containing metal nitrates, citric acid and ethylene glycol on Si (1 1 1) substrate, in which ethylene glycol was employed to enhance the affinity between the sol and the substrate. The perovskite phase was obtained by calcining corresponding precursor products at 650 ºC. The as-calcined nanoparticles were 50~100 nm in size. The as-calcined thin film showed uniform nano-porous morphology with the grain size of around 40 nm and the thickness of around 150 nm. The as-calcined nanotubes were around 100nm in diameter and up to several micrometers long