Magnetic relaxation of NP with dipolar interactions

Magnetic relaxation of a system of superparamagnetic particles weakly coupled by dipole-dipole interactions.
Pierre-Michel Déjardin
J. App. Phys. 110, 113921 (2011)

The relaxation time vs r as obtained from the diagonalization of the matrix A in Eq. (44) (solid line) and calculated with Eq.
(50) (dots) for k0 ¼ 0:05 and various values of h0 ¼ n=ð2rÞ. The dots on curve 1 are computed with Eq. (49).