Effect of substrate roughness on the surface free energy of sputter...
Effect of substrate roughness on the surface free energy of sputter deposited Superhydrophobic polytetrafluoroethylene coatings: A comparison of experimental data with different theoretical models, N. Selvakumar, H. C. Barshilia, K. S. Rajam, Journal of Applied Physics, 108 (2010) 13505, doi: 10.1063/1.3456165