Melting behaviours of nickel nanorods

By means of molecular dynamics simulations, we investigate the effect of size and axial crystal orientation on the melting behaviour of finitely and infinitely long nickel nanorods, using the quantum Sutton-Chen many body potential. It is found that the melting point of nanorods with decreased diameter is lower, regardless of finite or infinite length, which is in good agreement with the reported studies. The melting point also changes with the axial orientation of nanorods. The highest melting temperature is achieved for nanorods with axial crystal orientation 〈110〉, as the interval between any two layers along this direction is the shortest. For diameters of 3.6 and 4.9 nm, the finitely long nanorods exhibit a slightly lower melting point compared to infinitely long nanorods with the same diameter. For nanorods with diameter 2.3 nm, finitely long nanorods have higher melting points than infinitely long nanorods, due to reconstruction prior to melting. For diameters of 3.6 and 4.9 nm, nanorods (finite and infinite) have similar melting processes, but for nanorods with diameter 2.3 nm, shrinkage and reorganization takes place continuously during the melting process. For all nanorods, melting is found to initiate from surface atoms before diffusing inwards, into the internal portions.