MAGNETIC PARTICLE-PARTICLE INTERACTION IN FROZEN MAGNETIC FLUIDS

Magnetic resonance is used to study magnetic dipole particle-particle interaction in ionic water-based iron-manganese magnetic fluids. A set of six samples having particle concentration running from to 1.2X10(1 6) to 6.3X10(16) particles/cm(3) were frozen below room temperature an d analyzed in the range of 100-250 K. Average values of magnetic parti cle-particle interaction energy were obtained from the temperature dep endence of the resonance linewidth broadening. At 1.2X10(16) particles /cm(3) magnetic particle-particle interaction energy is found to be of the order of 1.2 meV, However, at 6.3X10(16) particles/cm(3) magnetic particle-particle interaction energy goes to 32 meV. The enhancement of the magnetic particle-particle interaction energy far beyond the li nearity is associated to cluster structuration. A one-dimensional mode l for cluster structuration is presented. (C) 1996 American Institute of Physics.