| Popis: |
The nonlinear magnetic excitation of anhysteretic and hysteretic magnetic nanoparticles was investigated in order to assess the requirements for the AC magnetic field applicator. Anhysteretic nanoparticles require strong DC bias and AC amplitude of about 100 kA/m, with the advantage of an asymmetric nonlinear response, i.e. with both even and odd higher harmonics generation. For hysteretic nanoparticles, an AC field with amplitude above the coercive field will be enough, but at the cost that only odd harmonics will be generated. A demonstrator of an AC magnetic field applicator using a neodymium ring permanent magnet was built and investigated. The proposed solution was proved suitable for deep one-sided detection of anhysteretic nanoparticles.The nonlinear magnetic excitation of anhysteretic and hysteretic magnetic nanoparticles was investigated in order to assess the requirements for the AC magnetic field applicator. Anhysteretic nanoparticles require strong DC bias and AC amplitude of about 100 kA/m, with the advantage of an asymmetric nonlinear response, i.e. with both even and odd higher harmonics generation. For hysteretic nanoparticles, an AC field with amplitude above the coercive field will be enough, but at the cost that only odd harmonics will be generated. A demonstrator of an AC magnetic field applicator using a neodymium ring permanent magnet was built and investigated. The proposed solution was proved suitable for deep one-sided detection of anhysteretic nanoparticles. |
