During the carburization process, absorption and incorporation of carbon atoms into the crystal structure of the copper matrix takes place. Maximum carbon content is considerably lower for liquid copper matrix compared to solid state matrix, and so, after heating above the melting point, the metal matrix becomes supersaturated with carbon atoms. HSMG® growth depends on the controlled carbon precipitation from the liquid metal matrix.
The growth progression begins with nucleation of single hexagonal flakes on the metallic substrate. During the nucleation process, the liquid matrix enables grain rotation and rearrangement, which brings about larger grain sizes and enhanced graphene properties. This process is completely controlled and enables the manufacture of graphene sheets with a definite number of layers.
Stable Negative Thermal Coefficient
The HSMG® samples exhibit anti-phase temperature resistance relationships during cyclic tests.
HSMG® temperature coefficient of resistance: −1.7⋅10−3 ÷ −4⋅10−4 [1/κ]
Efficient Gas Absorption
HSMG® exhibits vulnerability to reversible gas sorption (including selective hydrogen sorption from the gas mixture) which allows application of HSMG® as the functional material for future gas sensors.
Monolayer High Strength Metallurgic Graphene - HSMG®
Nomarski interference contrast image - Grain arrangement during nucleation
SEM - Evaluation of graphene grain size during growth process
HSMG® suspended on TEM grids