DIRECTIONAL ANISOTROPY IN CARBON PHASES PREPARED FROM FULLERITE C60 UNDER HIGH PRESSURES

Abstract

We present the study of anisotropy of elastic properties and structure for 2D polymerized rhombohedral and disordered atomic-based sp ² phases produced from C₆₀ at non-hydrostatic pressures and show that this anisotropy is a pressure-driven phenomenon. The elastic anisotropy, detected by the difference in the ultrasound velocities propagating along and across the loading axis, is directly confirmed by X-ray diffraction. The observed elastic anisotropy depends not only on uniaxial pressure component, but also on the absolute pressure value. This observation is treated in terms of dynamic and thermodynamic contributions of the uniaxial pressure component to mechanisms of atomic rearrangements under pressure.

Keywords:

• Fullerite
• Directional anisotropy
• 2D polymerized C₆₀
• Disordered sp2 carbon