Analysis of magnetite and related ferrites by means of magnetic after-effect-spectra

The magnetic aftereffect (MAE) spectra of magnetite (Fe3O4) and related spinel ferrites react most sensibly on smallest deviations of the crystal stoichiometry due to intrinsic or extrinsic lattice defects. Thus, the analysis of corresponding MAE spectra represents both an effective tool for quality control and classification of these materials and, moreover, a high-sensitive instrument for the detection and identification of respective lattice defects. The efficiency of this technique is demonstrated in the following on a series of instructive examples