Study on AC permeability and permittivity of manganese doped cobalt ferrite nanoparticles

This paper reports the significances of the negative real part of ac permeability and the transition of real part of ac permittivity. The paper also identifies the μ negative media and double negative media in the frequency range 3–120 MHz. The eddy current loss calculated from the measured complex permeability is found to diminish with increasing frequency which is an important factor to be considered for high frequency applications of these materials. (paper)