Papers by Keyword: Magnetic Viscosity

Abstract: This paper presents the investigation of the probability of changes in the magnetic properties of nanomaterials in strong fields of charged particles, neutrons and gamma rays. Co_xNi_1-xFe₂O₄ nanoparticles were obtained by the hydrothermal method using polyethylene glycol. Investigation of the properties of this material showed that its magnetic properties depend on the concentration of Со²⁺. In this work it is shown that the nuclear reactions taking place in the crystal lattice sites can change the relative concentration of the components of test material and, accordingly, its magnetic properties, including the coercive force.

Abstract: A new system for measuring magnetic viscosity in bulk hard magnetic materials base on a pulsed field method is presented. After the magnetizing field pulse, the stray field of the sample, which is proportional to the magnetic moment, is measured with a compensated set of two Hall probes. The set of Hall probes is driven with an AC voltage source and the Hall voltage is detected using a lock-in amplifier. By this method the system is able to measure the time dependence of the magnetization (viscosity). The magnetic viscosity coefficient (S) is obtained through a linear fitting of the magnetization decay versus ln t. Two typical Nd-Fe-B samples were measured and good agreement with the results from the traditional viscosity experiment was obtained.