Which gas serves as buffer gas in Laser ablation?

In ball milling method Tungsten Carbide and Precursor are taken in the ratio of ___________

In laser ablation ____ range is preferred

Nano materials shows which of the below properties/property due to increase in the surface to volume ratio

The enhancement in mechanical strength of nanomaterial say Copper compared to bulk is/are due to ________

For milling operations, what kind of environment is preferred?

____________ is used in sputtering method.