The Knight Shift

With the Knight shift we denote the shift of the NMR spectra of metals due to the hyperfine interaction. The Knight shift is defined as:

(3.32)

ref is the resonant magnetic field probed in a diamagnetic reference compound. In simple metals it is temperature independent and isotropic. In simple metal the Knight shift can be interpreted as being a consequence of the Fermi contact interaction:

(3.33)

with the Pauli susceptibility per atom and the square of the s-wave function at the nucleus averaged over the Fermi surface(The probability of having an electron from the Fermi surface at the place of the nucleus). But since the Knight shift does not appear in our measurements we don't want to go into further details. We suggest to read [#!carter!#] where other than only the contact interaction are take into account.

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