"Elastic properties" of magnetic fluids

The results of Mossbauer investigations of the viscous magnetic liquids at temperatures of 100-300 K are discussed. The investigated ferrofluids were the colloidal dispersions of magnetite particles with average diameters of 7.5 and 10 nm in silicone carrier fluid. Supposing that the intensity of th e Mossbauer line is determined by the factor f=f('.)f " (f' is Mossbauer fa ctor for magnetite powder; f " is a similar factor depending on oscillation s of particles in a liquid), we estimated the values of the factor f "(T) a t various temperatures. To describe the dependence f'(T), the Debye approxi mation was used. By means of the data on the dependence f "(T) the estimati ons of frequencies of particles oscillations Omega and "elasticity modulus" E of the investigated substances were obtained. (C) 1999 American Institut e of Physics. [S0021-8979(99)00511-3].