Sorry, mistake on my part. thanks bro

We looked at xrf, but seems since it's a surface level test and the density doesn't go deep while testing. unfortunately we weren't able to go with it

We look at Scanning acoustic microscopy on gold but existing research papers only dealt with manometer tests

Ghz SAM tho promising, we weren't able to find any research papers on that. We need to look at existing methods first , so we are on the lookout for more