The Effect of Catalyst Thickness and the Hydrogen Annealing Time on Spin Capability of Carbon Nanotube Forest with a Fast Temperature Ramping Rate CVD System

Abstract

In this paper, we report the effects of iron (Fe) thickness and the hydrogen (H2) annealing time on the spin-capability of vertically aligned carbon nanotube (CNT) forest. Using a chemical vapor deposition chamber with a magnetic arm and mobile furnace, quick heating and cooling were done on the sample. For the growth process of carbon nanotube forest, the sample was moved from room temperature to 780 °C in 3 seconds in helium (He) environment, and H2 and acetylene (C2H2) were used as annealing gas and carbon source, respectively. To study the effect of Fe thickness on spin-capability, 1.5, 2.5, and 3.5 nm of Fe thin film was deposited using e-beam deposition tool on top of a thin aluminum oxide (Al2O3) layer. Also, the duration of hydrogen annealing time for the Fe film to form Fe nanoparticles were varied from 10 ~ 60 seconds. Fe film thickness of 2.5 nm and 30 seconds of H2 annealing time resulted in well-spinning vertically aligned carbon nanotube forest.