Ò
Dipole-dipole interactions, which are weaker
and long-range forces.
Ò
Dipolar interactions are given by
Ò
->H
dd =
(
μ
0
/4
π
)
Σ
[
3(
μ·
r
ij
)(
μ·
r
ij
)-
μ
i
·μ
j
]
Ò
r
ij
3
Ò
Where
r
ij
is the displacement between any two
spins
S
i and
S
j.
Ò
