Paracrystalline graphite with combined high strength, plasticity and anomalous conductivity

Abstract

Paracrystallization provides a route to achieving synergistic properties beyond conventional property trade-offs, but applying it to layered materials is challenging due to strong bonding anisotropy. Here, we report the synthesis of paracrystalline graphite, a paracrystalline state realized in a layered material, through a high-pressure-driven “local graphitization” of C60 crystals. Structural characterization and reverse Monte Carlo simulations reveal a three-dimensional network of graphite-like clusters with ~70° interlamellar angles. This architecture delivers a combination of properties, including an isotropic hardness of 33.7 GPa, a plastic strain of 12% enabled by bond conversion and cluster reorganization, and weakly temperature-dependent semimetallic conductivity that varies by less than 12% from 4 to 450 K. Bridging the gap between crystalline graphite and noncrystalline carbon, this paracrystalline system demonstrates a viable pathway for designing materials with tailored multifunctional properties by engineering medium-range order. The authors synthesize paracrystalline graphite with a three-dimensional interwoven graphitic network. It combines a hardness of 33.7 GPa, a plastic strain of 12% and semimetallic conductivity varying by less than 12% from 4 to 450 K.