NMR in metals at low temperatures with particular emphasis on the finite skin depth

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Abstract

In modern cryostats it is possible to obtain up to 50% of the nuclear saturation magnetization for metallic samples by applying static magnetic fields Bz ∼ 0.1 T at sample temperatures of the order of ∼0.1 mK. The resulting strong exchange and demagnetization fields cause considerable nonlinear corrections to the dynamics of the magnetization. In NMR experiments additional complications arise due to spatial variation of the magnetization caused by the finite penetration depth δ of the rf-field. The consistent description of a pulsed NMR experiment is therefore based on the solution of the coupled system of Bloch's and Maxwell's equations. The included nonlocality of the exchange interaction leads to the possibility of spin wave excitations. In particular we concentrated on Cu and Tl, both with two NMR isotopes and with a very strong indirect exchange for the latter. It turns out that in particular the voltage signal in a pick-up coil is well suited to reveal the various linear/nonlinear interaction mechanism in our confined geometry (cylinder).

References (4)

  • Ekstro¨mJ.P. et al.

    Physica

    (1979)
  • VonsovskiiS.V.

    Ferromagnetic Resonance

    (1966)
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