Influence of annealing process on surface micromorphology of carbon–nickel composite thin films

Fractal Analysis on Surface Topography of Thin Films: A Review

The topographies of various surfaces have been studied in many fields due to the significant influence that surfaces have on the practical performance of a given sample. A comprehensive evaluation requires the assistance of fractal analysis, which is of significant importance for modern science and technology. Due to the deep insights of fractal theory, fractal analysis on surface topographies has been widely applied and recommended. In this paper, the remarkable uprising in recent decades of fractal analysis on the surfaces of thin films, an essential domain of surface engineering, is reviewed. By summarizing the methods used to calculate fractal dimension and the deposition techniques of thin films, the results and trends of fractal analysis are associated with the microstructure, deposition parameters, etc. and this contributes profoundly to exploring the mechanism of film growth under different conditions. Choosing appropriate methods of surface characterization and calculation methods to study diverse surfaces is the main challenge of current research on thin film surface topography by using fractal theory. Prospective developing trends are proposed based on the data extraction and statistics of the published literature in this field.

Influence of heating rate, temperature, pressure on the structure, and phase transition of amorphous Ni material: A molecular dynamics study

The present article is aimed to investigate influence of the heating rate, temperature (T), pressure (P) on the structure and phase transition of amorphous Ni material with heating rate 2 × 105, 2 × 106 and 2 × 107 K/s at T = 300 K; T = 300, 400, 500, 600, 700, 800, 900 and 1000 K at heating rate 2 × 106 K/s; T = 300, 621 and 900 K at P = 1, 2, 3, 4 and 5 GPa by molecular dynamics simulation method with Sutton-Chen embedded potential and periodic boundary conditions. The structure of amorphous Ni material determined through the radial distribution function, the total energy, the size and the average coordination number. The phase transition and the glass transition temperature determined through the relationship between the total energy and temperature. The result shows that when the heating rate increases, the first peak's position for the radial distribution function is 2.45 Å and a constant, the first peak's height, the total energy and the size increase, the average coordination number decreases from 13 to 12. When temperature increases from 300 to 1000 K at P = 0 GPa, the position decreases from 2.45 Å to 2.40 Å, the average coordination number is 13 and a constant, glass transition temperature is 631 K, the total energy increases, the size increases and happens the phase transition from the amorphous state to the liquid state. When pressure increases from 0 GPa to 5 GPa at T = 300, 621 and 900 K, the position decreases, the height increases, the total energy increases, the size decreases, the average coordination number decreases from 13 to 12, that shows with amorphous Ni material when increasing heating rate, T, P lead to structural change, phase transition of materials is significant.