At this time, I am trying to learn a detailed understanding of the physics of GMR especially in Co/Cu thin film multilayers.
Here is the best book on the subject.
Handbook of spin transport and magnetism, by E Y Tsymbal Igor Zutic (eds.).
I am sending it to you right away using your RG email. Let me know if you get it safely. If not (it has 46Mb), I will try gmail (sometimes it works better).
Although there are many interesting books in the literature, let me try to give you one simple idea of what giant magnetoresistance is.
In metallic multilayers as you mentioned, Co/Cu/Co, depending of the width of the Cu (called spacer) you can get the Co layers to have the magnetization parallel(also called ferromagnetic configuration) or antiparallel (antiferromagnetic) due to the RKKY electronic interaction.
If you are in the antiferromagnetic configuration and you apply one external magnetic field (even weak, for example 0.5 Oes Earth magnetic field) getting a ferromagnetic configuration. The conductivity also change very drastically. Notice that this is a very different form to induce electric current in a circuit without employing the Faraday's law.
I hope that this can help to understand this physical phenomenon in a simple form.
Dear Prof. Daniel Baldomir,
First, thank you for your response. I agree that resistivity of thin film change as a function of external magnetic field. This effect because the change of magnetization configuration from antiparallel to parallel. I have read in some references, It can be understood to relate to Spin-dependent scattering. At his time, I am trying to learn the mechanism of spin-dependent scattering in magnetic systems.
Cheers,
Indra
In giant magnetoresistance is not used in detail (electron-electron scattering) the scattering but how the "scattering" of an electron gas, obviously providing spin by means of the RKKY (Ruderman-Kittel-Kosiya-Yosida) interaction among spins. In fact, the localized inner d or f shell electron spins in a metal by means of an interaction through the conduction electrons contained in the spacer layer, which is separating the two ferro/antiferromagnetic layers. Thus the magnetic polarization of the electrons d or f (i.e. localized) depend strongly of the distance between the magnetic layers, being with parallel or antiparallel configuration and the free electrons.
If you want to know how the electron-electron scattering works, you can go to the Mott scattering which is the part complementing the Rutherford part(charge) and you can see that the parallel spins have different cross section than the ones antiparallel. The first proof was in
Hofstadter, R., et al., Phys. Rev. 92, 978 (1953)
for electron-nucleus.
But this microscopic treatment is far of the usual giant or colossal magnetoresistance.
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