Mössbauer effect and magnetism of single domain Fe3O4particles in ferrofluids

Autor:	K.M.B. Alves, J. Popplewell, S. W. Charles, A. Tari, D St P Bunbury
Rok vydání:	1983
Předmět:	Ferrofluid Materials science Spin glass Mössbauer effect Condensed matter physics Magnetism Remanence General Physics and Astronomy Single domain Magnetic susceptibility Néel temperature
Zdroj:	Journal of Applied Physics. 54:3351-3358
ISSN:	1089-7550 0021-8979
DOI:	10.1063/1.332448
Popis:	Three ferrofluids, consisting of suspensions of Fe3O4 particles of ≂100–200 A diameter in diester, hydrocarbon, and water have been investigated at temperatures 4.2–300 K by means of Mossbauer effect and magnetic measurements. The magnetic data displays almost all the features observed in the spin glasses. The Neel model is used to explain the behavior of the fluids. From the temperature variation of the initial susceptibility and the isothermal remanence, K=(3.5±0.7)×105 erg/cc and D0=(80±5) A are obtained for the anisotropy constant and the median diameter, respectively, of the diester based ferrofluid. The ac susceptibility gives K=3×105 erg/cc and D0=92 A. For the water based ferrofluid measurements give K=1.5×105 erg/cc. Values obtained from Mossbauer measurements for K and D0 agree with those obtained from magnetization–susceptibility data.
Databáze:	OpenAIRE
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