Published online by Cambridge University Press: 03 March 2011
Microcontact impedance spectroscopy in conjunction with conventional impedance techniques has been performed to elucidate microstructural and compositional inhomogeneities in polycrystalline Mn–Zn ferrites. Microcontact studies reveal the occurrence of oxygen stoichiometry gradients in these typically prepared ferrite ceramics together with a strong spatial resistance variation from boundary to boundary. This leads to a reinterpretation of the conventional impedance spectra of ferrites.