• S K Panda

Articles written in Bulletin of Materials Science

• Carbon nanotube synthesis from propane decomposition on a pre-treated Ni overlayer

Growth of carbon nanotubes (CNTs) was performed by atmospheric pressure chemical vapour deposition (APCVD) of propane on Si(111) with a pre-treated Ni overlayer acting as a catalyst. Prior to the growth of CNTs, a thin film of Ni was deposited on Si(111) substrate by evaporation and heat treated at 900°C. The growth of nanotubes was carried out at 850°C using propane as a source of carbon. Distribution of the catalyst particles over the Si substrate was analysed before and after heat treatment by atomic force microscopy (AFM). The X-ray diffraction (XRD) pattern of the grown material revealed that they are graphitic in nature. Field emission scanning electron microscopy (FESEM) was used to investigate the growth process and it was found that a catalytic particle was always situated at the tip of the tube thus implying a tip growth mechanism. Evidence for the presence of radial breathing mode from multi-wall nanotubes (MWNTs) in the grown sample was obtained from micro-Raman analysis. Finally, high-resolution transmission electron microscopic (HRTEM) analysis confirmed that the graphene layers of the CNTs are well ordered with typical 0.34 nm spacing.

• Catalytic synthesis of ZnO nanorods on patterned silicon wafer—An optimum material for gas sensor

ZnO nanorods have been synthesized over etch-patterned Si (110) wafer using annealed silver thin film as growth catalyst. The growth of ZnO nanorods were performed by a two-step process. Initially, the deposition of Zn thin film was done on the annealed silver catalyst film over etch-patterned Si (110) substrate by thermal evaporation, and then annealed at 800°C in air. The etching of the patterned Si (110) wafers was carried out by 50% aqueous KOH solution. The samples were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction, Raman spectroscopy and room temperature photoluminescence spectroscopy. V’ shaped grooves with no undercut were formed after etching due to the anisotropic nature of the KOH etchant. The etch-patterned wafer was used to provide larger surface area for ZnO growth by forming V’-grooves. This ZnO film may be predicted as a very good material for gas sensor.

• # Bulletin of Materials Science

Volume 43, 2020
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019