Dual-functional magnetic and field emission properties of γ-Fe 2O3 coated carbon nanotubes core-shell structures

Abstract

A γ-Fe2O3 coated carbon nanotube (CNT) core-shell structure with dual magnetic and field emission properties was successfully fabricated by a simple one-step technique. The γ-Fe 2O3 shell is deposited on vertically aligned multi-walled CNTs by chemical vapor deposition using ferrocene as the precursor at process temperatures of 200, 400 and 600°C. At 400°C, the γ-Fe 2O3 shell formed a polycrystalline coating of polygonal nanoparticles on the CNTs. Enhanced field emission performance was observed with a threshold field of 4.7 Vμm-1 compared to pristine CNTs at 5.6Vμm-1. Magnetic measurements revealed that the γ-Fe 2O3-CNT composites demonstrated ferrimagnetic behavior with high saturation magnetization of 52.3 emu/g and coercivity of 237 Oe at room temperature. © 2014 The Electrochemical Society.