Properties of Cu/Au thin films under temperature gradient: a molecular dynamics study

The thin films with modulation period of 1.8 nm Cu/3.6 nm Au are obtained via deposit method and ideal created based on lattice constant to examine their characteristics under temperature gradient based on molecular dynamics simulations. The coherent lattice interface is found both at deposit and ideal thin films after annealing. Also, the vacancies is found clearly in the deposit thin films. The defect thin films would weak the energy transportation in the coatings. The vacancies and lattice mismatch could enlarge the mobility of atoms and result in the failure of coating under the thermal stress. The power spectrum of atoms' movement showed no apparent rule for phonon transportation in thin films.