Dear All,

I would like to ask why does the color of the argon plasma during sputtering
changes form light purple to bright blue as the deposition power is
increased or the working pressure is increased to about 0.1 m bar? Is the
shift in color towards deep blue, due to formation of increased number of
energy states...? if so  how is it happening with increased power and/or
with increased working pressure..?

Thanks in advance....

Debashis Maji,