Effect of Magnetic and Geometric Properties on the Time of Magnetic Relaxation of Superparamagnetic Core-Shell Nanoparticles

Abstract

Within the frame of two-phase superparamagnetic nanoparticles the effect of magnetic and geometric properties of superparamagnetic nanoparicles on the time of their magnetic relaxation has been defined. With increasing of volume, elongation of nanoparticle and relative volume of inclusions the time of relaxation grows rapidly. Metastability conditions of magnetic states have been developed. Growth of exchange constant magnitude of interphase interaction results in increasing of relaxation time regardless of exchange constant sign. Keywords: superparamagnetic particles, core-shell nanoparticles, relaxation time, magnetic states, critical field, metastable magnetic states, interphase exchange interaction.