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 Mo2C 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 Mo2C. The surface of the Mo2C 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.