Formation of encapsulated molybdenum carbide particles by annealing mechanically activated mixtures of amorphous carbon with molybdenum

Abstract

The investigation of morphological and structural changes during high-energy ball milling and thermal annealing of mixtures of amorphous carbon and molybdenum demonstrated that the activation leads to the formation of a nano-size carbide Mo 2 C phase. Morphological characteristics of the annealed, mechanically activated amorphous carbon–molybdenum samples depend on the time of preliminary mechanical activation. Annealing of amorphous carbon–molybdenum samples after preliminary mechanical activation, at a temperature of 860 °C, caused the formation of nano-sized encapsulated particles of molybdenum carbide Mo 2 C. The surface of the Mo 2 C nanoparticles was coated with a shell composed of hexagonal polyaromatic carbon 5–20 nm thick. The size of the encapsulated particles varies within a rather broad range from 10 to 20 nm to several hundred nanometers.