The effect of particle interactions on Curie–Weiss behavior in ferrofluids

摘要: The initial susceptibility of a number Fe3 O4 particle ferrofluids with volume concentrations, e=0.08, 0.07, 0.05, 0.03, 0.02, and 0.01 (prepared by diluting stock fluid Ms =40 kA m−1) has been measured in the temperature range 220–450 K. mean sizes Dm (magnetic) Dp (physical) are 74 81 A, respectively. exhibit Curie–Weiss‐type behavior negative (Neel) intercepts To . form Curie–Weiss is interpreted as arising from interactions which strong enough to reduce below noninteracting value measurements. It suggested that lead formation closed structures zero moment field and, would be case for an antiferromagnetic material, leads ‘‘Neel’’ temperature. Negative values thus characteristic interacting system.