Slides

More documents

Recommendations

Info

4. Magnetic moments for transition metal ions Metal ions in salts : Example: FeCl 2 with an ionic state: Fe 2+ • For atomic Fe the electronic configuration is 3d 6 4s 2 • The s-electron go into the ionic bond, remaining 3d 6 , i.e. 6 electrons in the d-shell • Level scheme according to Hund‘s rule: mL3d 6 -2 } 1 -1 S = 4 ⋅ = 2 2 0 L = 2 1 J = L + S = 4 2 Spectroscopic term: 5 D4 • Expected g J value: g J = 3 2 + S ( S + 1) - L( L + 1) 2J ( J + 1) = 3 2 for S = L H. Zabel 3. Lecture: Local Moments 10
Calculated effective magnetic moment p J If we consider spin only: 3 3 = gJ J( J + 1 ) = 4 . 2 2 ( 4+ 1) = 20 = 6 7 p S = g S S( S + 1 ) = 2 2 ⋅ 3 = 4. 89 Experimentally determined: p exp = 5.4 The experimentally determined value is closer to S p then to J p In most cases of transition metal ions the orbital momentum appears to be quenched. H. Zabel 3. Lecture: Local Moments 11
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: L and S according to Hund‘s Rule
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 and 26: Consequences from a strong crystal
Page 27 and 28: 6. Magnetic moment of rare earth io
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

Slides

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?