Aggregated diamond nanorods, the densest and least compressible form of carbon

Abstract

We report the synthesis of aggregated diamond nanorods (ADNRs) from fullerene C60 at 20(1) GPa and 2200 °C using a multianvil apparatus. Individual diamond nanoroads are of 5–20 nm in diameter and longer than 1μm. The x-ray and measured density of ADNRs is ∼0.2%–0.4% higher than that of usual diamond. The extremely high isothermal bulk modulus KT=491(3)GPa [compare to KT=442(4)GPa of diamond] was obtained by in situ x-ray diffraction study. Thus, ADNRs is the densest among all carbon materials and it has the lowest so far experimentally determined compressibility.