ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
In soft magnetic ferrites, the dispersion of the dynamic magnetic susceptibility and the maxima in the loss factor are known to be caused by the electron hopping between Fe2+ and Fe3+ ions.1 However, in the manganese ferrite system MnxFe3−xO4, two distinct electronic relaxation phenomena are reported for the compositions x=0.8, the first with an activation energy of about 0.015 eV and the second with Ea =0.06 eV.2 The elementary processes of these two relaxations are not well established; inter- and intra-atomic electron transitions between the iron ions are claimed as an interpretation,2 whereas electron transitions between iron and/or manganese ions are another interpretation.3 In the present paper, we report a detailed investigation of the magnetic relaxation effects in the manganese ferrite system, in combination with electrical conductivity measurements. The obtained results are interpreted on the basis of electronic hopping between Fe2+ and Fe3+ ions only, taking into account the effect of ionic disorder on octahedral sites, which is also the cause of the Coulomb gap formation at the metal-semiconductor transition in pure Fe3O4.4
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.338624
Permalink
