for giant magnetoresistance with 3 layers suppose Fe-Cu-Fe, and suppose we take room temperature (300K) and moderate layer thickness (eg Fe = 30 Amstrong, Cu = 20 Amstrong), what is the typical magnetoresistance we get? I mean the maximum resistance (in ohms) when the magnetization of the FM layers are antiparallel (i am not asking the GMR ratio delta r/ro). Is it in the order of few tens of ohms, hundreds of ohms, kilo ohms ? i just want rough estimate. all references i saw talk about the gmr ratio only, not the actual resistance. thank you.