Simulation of chemical bond distributions and phase transformation in carbon chains

In the present work we develop a Monte Carlo algorithm of the carbon chains ordered into 2D hexagonal array. The chemical bond of the chained carbon is computed from 1 K to 1300 K. Our model confirms that the beta phase is more energetic preferable at low temperatures but the system prefers to switch into alpha phase at high temperatures. Based on the thermal effect on the bond distributions of the carbon chains, the bond softening temperature is observed at 500 K. The bond softening temperature is higher in the presence of interstitial doping but it does not change with the length of nanowire. The elastic modulus of the carbon chains is 1.7 TPa at 5 K and the thermal expansion is +7 × 10−5 K−1 at 300 K via monitoring the collective atomic vibrations and bond distributions. Thermal fluctuation in terms of heat capacity as a function of temperatures is computed in order to study the phase transition across melting point. The heat capacity anomaly initiates around 3800 K.

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