Detonation synthesis of carbon-encapsulated magnetic nanoparticles

Carbon-encapsulated iron-based nanoparticles were produced by detonation of mixtures of high explosive and iron tristearate in a vacuum chamber. The collected products were analyzed by HRTEM, XRD, Raman spectroscopy and magnetic measurement. The results indicate that a core-shell structure is formed, in which iron/iron carbide cores are encapsulated with graphitic shells with a thickness of 3-10 nm. The mass ratio of high explosive to iron tristearate, leading to different detonation pressures and temperatures, has played an important role in the formation of carbon encapsulated nanoparticles. With the increase of the mass ratio, the number of the graphitic coating layers and the size of carbon encapsulated nanoparticles decreases. Different mass ratios create different core compositions. The carbon encapsulated nanoparticles exhibit ferromagntic behavior.