Ultrastrong conductive in situ composite composed of nanodiamond incoherently embedded in disordered multilayer graphene

Abstract

Traditional ceramics or metals cannot simultaneously achieve ultrahigh strength and high electrical conductivity. The elemental carbon can form a variety of allotropes with entirely different physical properties, providing versatility for tuning mechanical and electrical properties in a wide range. Here, by precisely controlling the extent of transformation of amorphous carbon into diamond within a narrow temperature–pressure range, we synthesize an in situ composite consisting of ultrafine nanodiamond homogeneously dispersed in disordered multilayer graphene with incoherent interfaces, which demonstrates a Knoop hardness of up to ~53 GPa, a compressive strength of up to ~54 GPa and an electrical conductivity of 670–1,240 S m–1 at room temperature. With atomically resolving interface structures and molecular dynamics simulations, we reveal that amorphous carbon transforms into diamond through a nucleation process via a local rearrangement of carbon atoms and diffusion-driven growth, different from the transformation of graphite into diamond. The complex bonding between the diamond-like and graphite-like components greatly improves the mechanical properties of the composite. This superhard, ultrastrong, conductive elemental carbon composite has comprehensive properties that are superior to those of the known conductive ceramics and C/C composites. The intermediate hybridization state at the interfaces also provides insights into the amorphous-to-crystalline phase transition of carbon.

Theoretical and Experimental Advances in High-Pressure Behaviors of Nanoparticles

“…With research on high-pressure phenomena in NPs becoming increasingly widespread, we expect that researchers from various backgrounds and expertise will join forces in this fast-growing field. For example, several groups have reported the synthesis of advanced diamond related nanomaterials from high-pressure and high-temperature (HPHT)-treated carbon-based materials. − Such techniques have the potential to generate exotic materials in bulk, as well as to produce high-pressure material phases like those in naturally occurring diamond inclusions. In addition, there have been recent studies on the high-pressure behaviors of metal–organic framework (MOF) materials. − MOFs are crystalline microporous materials constructed from metal ions/clusters with connecting organic ligands − that possess fascinating properties including versatile tunability, large porosity and surface area, and precise control on pore-sizes .…”

Nanobubble-induced significant reduction of the interfacial thermal conductance for few-layer graphene

“…This potential has been effectively employed in the exploration of both the mechanical and thermal properties of graphene. 30,31 The harmonic spring potential is utilized to capture the interaction between two bonded atoms. Furthermore, the interaction between different atoms is characterized by the 12-6 Lennard-Jones potential.…”

Superhard bulk C4N3 compounds with metal-free magnetism assembled from two-dimensional C4N3: a first-principles study

“…As a result, some such materials have been reported, for instance, a composite consisting of nanodiamond dispersed in disordered multilayer graphene exhibits a high electrical conductivity of 670-1240 S m À1 at room temperature, carbon polymorphs, B 2 C 3 N 2 and metal borides (i.e., tungsten tetraboride, iron tetraboride and molybdenum boride) show metallic behavior, etc. [12][13][14][15][16][17][18][19][20] On the other hand, magnetic properties are another important feature for materials in their applications. Superhard materials with magnetic properties could be utilized in many special fields, such as magnetic bearings.…”