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AM: Magnetismus
AM 16: Magnetische Meßtechnik
AM 16.4: Talk
Thursday, March 26, 1998, 10:45–11:00, H10
Magnetic properties of human liver and brain ferritin — •S. M. Dubiel1, B. Zablotna-Rypień1, J. Mackey2, and J. M. Williams2 — 1Faculty of Physics and Nuclear Techniques, AGH University, PL-30-059 Kraków — 2Department of Physics, University of Sheffield, Sheffield
Lyophilised samples of human liver and brain (globus pallidus) were investigated by means of electron microscopy (EM), Mössbauer spectroscopy (MS) and SQUID magnetometry. Using MS the form of iron present was identified and its concentration determined as 2.4(5) mg/g for the liver, and 1.5(3) mg/g for the brain. Based on the SQUID measurements carried out between 5 and 300 K the average blocking temperature, <TB> was determined as 6.7 K for the liver and 8.8 K for the brain. Using this data and knowing the average volumes of the ferritin cores from EM, the uniaxial anisotropy constant was estimated as 104 erg/cm3 for the liver ferritin and 105 erg/cm3 for the brain one. From the dependence of <TB> on external magnetic field it was concluded that the ferritin cores do not interact with each other.