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Transition metals: determination of g-value EPR – FMR resonance frequency: ω = gµ B B res g-value from the slope. Ratio of magnetic moments: m m L S = g − 2 2 M. Ulmeanu et al. PRB 69 (2004) Most metal ions show a g-value of 2.1 - 2.2. Thus, in reality the orbital contribution is on the order of 0.1 – 0.2, i.e. orbital moment is not completely quenched. Remaining orbital moment is responsible for magnetic anisotropy. H. Zabel 3. Lecture: Local Moments 26
6. Magnetic moment of rare earth ions Crystal field splitting in rare earth ions is small in the meV-range: • The inner 4f - shell is well screened from the outer shells 5s 2 p 6 6s 2 , which take part in the chemical bonding. Therefore, 4f electrons are more localized. • LS – coupling is strong because of higher Z atoms compared to the 3d atoms. Here the limit holds: ∆
Page 1 and 2: 3. Lecture: Basics of Magnetism: Lo
Page 3 and 4: 1. Local moments of magnetic ions O
Page 5 and 6: Nomenclature for spectroscopic term
Page 7 and 8: Overview of 3d-metal ions m L = H.
Page 9 and 10: L and S according to Hund‘s Rule
Page 11 and 12: Calculated effective magnetic momen
Page 13 and 14: Magnetic moments of 3d-transition m
Page 15 and 16: Crystal electrical field splitting
Page 17 and 18: Octahedral crystal field Max. proba
Page 19 and 20: Adding all energy terms + H CF λL
Page 21 and 22: Degeneracies in crystal fields p-le
Page 23 and 24: High spin - low spin case • For d
Page 25: Consequences from a strong crystal
Page 29 and 30: Overview of 4f-rare earth ions m L
Page 31 and 32: Example: Ce 3+ (one electron in the
Page 33 and 34: Comparison of calculated and measur
Page 35 and 36: LS splitting for Sm LS -splitting Z

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