Experimental determination and molecular dynamics simulation of specific heat for high temperature undercooled liquid

The accurate data of specific heat are of great significance in the thermodynamic analysis of phase transformation. Here, we report the experimental and calculated specific heat of liquid Ni_90.1Si_9.9 alloy by electromagnetic levitation drop calorimeter and molecular dynamics calculation, respectively. The experimental result, 39.54 J mol^-1 K^-1, is in good agreement with the calculated value of 38.03 J mol^-1 K^-1, and there exists only a little difference between them. The calculated undercooling range of 0 ∼ 623 K is much wider than the experimental range of 0 ∼ 218 K. The undercooled liquid structure of this alloy is analyzed according to the total and partial pair distribution functions, which show that the in-order degree of atom distribution enhances from normal liquid to undercooled liquid. The Si atoms are homogeneously dispersed among the Ni atoms, whereas the average distance among Ni atoms changes little.