Low concentration magnetic nanoparticle and localized magnetic centers in different materials: studies by FMR/EPR method

Purpose: The aim of this review is recapitulating the temperature dependence of FMR/EPR spectra of low concentration of magnetic nanoparticles and ultralow concentration localized magnetic centers (defects, free radicals, the lower oxidation state of titanium ions) in different materials.Design/methodology/approach: Reorientation processes correlated and isolated spin systems during changing temperature could inform about physical properties of the materials. The FMR/EPR is very usefully method for characterization novel materials as polymers/copolymers, nanotubes, TiN, TiC, Ti-Si-C-N, TiO2, Me-Fe-V-O, nFe2O3/(1-n)ZnO or an extended free radicals networks.Findings: The intense almost symmetrical FMR resonance line of low concentration of magnetic nanoparticles are observed which essential are changed at different temperatures. The EPR spectra of low concentration localized magnetic nanoparticles is shown that the relaxation processes are different than for magnetic nanoparticles embed in polymer matrixes. A very low concentration of magnetic nanoparticles and localized magnetic moments could modify its physical properties (magnetic, conductivity or mechanical).Research limitations/implications: Composite systems containing magnetic nanoparticles and localized magnetic moments promise the potential for high-density data storage, biomedical applications, catalysis, building materials, photovoltaic, metallurgy and nanotechnology sensor materialisation, among other envisaged utilisations.Originality/value: Continue attempting to decipher the mystery and fruitfulness of magnetic nanoparticle and localized magnetic nanoparticles distributions.