Abstract
Non-thermal effects caused by ultrafast lasers and swift ions in materials are very intriguing, which is of both scientific interest and technological importance. However, the underlying physics of non-thermal effects on ultrafast process remains unclear and the proposed mechanisms have been controversial. Based on the perturbation approximation under tight-binding theory, the non-thermal effects on tungsten (W) are extensively studied. We demonstrate that the non-thermal effects stemmed from the intense electronic excitations induce dramatic decrease in the melting point of W crystal, as well as non-thermal melting inside the W slab. Our analysis shows that the non-thermal forces are essentially responsible for the drop of melting point of the bulk system. Remarkably, the non-thermal effects combined with surface effects on a W film enhance the ordering of the direction of atomic motion near the surface, preventing melting near the surface area, but leading to non-thermal melting in the interior area of the film. Our work also exhibits a unified relationship between the non-thermal melting and the interatomic forces. This relationship is universal in metals and semiconductors irradiated by ultrafast lasers or fast ions, and has been well established long before.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.