wherein {HEAD ~ a thickness} of {TAIL ~ the Mg Ag layer} is in a range of 170 Å to 200 Å, 
of
wherein { HEAD ~ a thickness } of { TAIL ~ the Mg Ag layer } is in a range of 170 Å to 200 Å ,
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH