Contactless conductivity of nanoparticles from electron magnetic resonance lineshape analysis

摘要

A contactless method to determine the electrical conductivity of nanoparticles is presented. It is based on the lineshape analysis of electron magnetic resonance signals which are 'Dysonian' for conducting samples of sizes larger than the skin depth. The method is validated by measurements on a bulk sample of La_(0.67)Sr_(0.33)MnO_3 where it gives values close to those obtained from direct measurement of conductivity and is then used to determine the conductivity of nanoparticles of La _(0.67)Sr_(0.33)MnO_3 dispersed in polyvinyl alcohol as a function of temperature.