Home (magnetism)

Effective Magnetic Moments

Reference = N.W.Ashcroft, N.D. Mermin, Solid State Physics, Saunders College Publishing, USA, (1976) pages 657 and 658.
L = total orbital angular momentum (quantum number of orbital angular momentum)
S = total electronic spin angular momentum (quantum number of ...)
J = total electronic angular momentum (quantum number of ...)

Ground State Term: 2S+1XJ, X="S" for L=0, X="P" for L=1, X="D" for L=2, X="F" for L=3, Term Symbol - Wiki.

calculated peff = g(J,L,S) sqrt[J(J+1)], g = 3/2 + (1/2)[( S(S+1)-L(L+1) )/J(J+1)] = 2.0 za S=J.

From Curie Constant C: peff = \sqrt(8*C), units: C = X*T in emu K/mol, [peff] = BM (Bohr magneton).

REAR EARTH IONS:
Element Basic electron configuration Ground State Term calculated peff measured peff
La 4f0 1S 0.00 diamagnetic
Ce 4f1 2F5/2 2.54 2.4
Pr 4f2 3H4 3.58 3.5
Nd 4f3 4I9/2 3.62 3.5
Pm 4f4 5I4 2.68 -
Sm 4f5 6H5/2 0.84 1.5 (due to low-lying J-multiplets)
Eu 4f6 7F0 0.00 3.4 (due to low-lying J-multiplets)
Gd 4f7 8S7/2 7.94 8.0
Tb 4f8 7F6 9.72 9.5
Dy 4f9 6H15/2 10.63 10.6
Ho 4f10 5I8 10.60 10.4
Er 4f11 4I15/2 9.59 9.5
Tm 4f12 3H6 7.57 7.3
Yb 4f13 2F7/2 4.54 4.5
Lu 4f14 1S 0.00 diamagnetic

The IRON (3d) GROUP IONS:
Ion Basic electron configuration Ground State Term calculated peff (J=S) calculated peff (J = |L+-S| measured peff
Ti3+ 3d1 2D3/2 1.73 1.55 -
V4+ 3d1 2D3/2 1.73 1.55 1.8
V3+ 3d2 3F2 2.83 1.63 2.8
V5+ does not carry any local magnetic moment on d-electrons
V2+ 3d3 4F3/2 3.87 0.77 3.8
Cr3+, V2+ 3d3 4F3/2 3.87 0.77 3.8 (3.7 for Cr)
Mn4+ 3d3 4F3/2 3.87 0.77 4.0
Cr2+, V2+ 3d4 5D0 4.90 0 4.8
Mn3+ 3d4 5D0 4.90 0 5.0
Mn2+ 3d5 6S5/2 5.92 5.92 5.9
Fe3+ 3d5 6S5/2 5.92 5.92 5.9
Fe2+ 3d6 5D4 4.90 6.70 5.4
Co2+ 3d7 4F9/2 3.87 6.54 4.8
Ni2+ 3d8 3F4 2.83 5.59 3.2
Cu2+ 3d9 2D5/2 1.73 3.55 1.9
Ce3+ 4f1 2F5/2 No quenching 2.54 2.4

Ni1+ has S=1/2 and d9 as Cu2+. Reference PRL (Ni1+/Ni2+).