We have successfully synthesized l-

We have successfully synthesized l-histidine capped iron oxidenanoparticles in one pot process. The final product was analyzed for composition, microstructure, ac–dc conductivity performance,and dielectric permittivity. l-Histidine is assessed to be covalentlybonded to the iron oxide nanoparticle surface via carboxyl groups.Thermal analysis revealed that magnetic nanoparticles showed cat-alytic effect that caused an early degradation/decomposition ofthe l-histidine capping. Near spherical morphology was assessedby TEM and particle size calculated from TEM analysis and crys-tallite size calculated from XRD analysis reveal single crystallinenature of iron oxide NPs. Magnetic measurements reveal the super-paramagnetic character of the nanocomposite. The ac conductivityshowed a temperature independent behavior at low frequenciesand temperature dependant behavior at high frequencies whichis an indication of ionic conductivity. The dc conductivity of thenanocomposites is found to obey the Arrhenius plot with activa-tion energy of 0.934 eV. The ac and dc conductivity measurementsrevealed semiconductor conduction characteristics, and varioustrends were observed, as a function of frequency and temperature,revealing different mechanisms dominating based on the tempera-ture dependant reorganization of the nanocomposite. Permittivitymeasurements showed increasing dielectric constant with increas-ing temperature as expected from semiconductors. Analysis ofelectrical modulus and dielectric permittivity functions suggestthat ionic and polymer segmental motions are strongly coupledin the nanocomposite.