The Effect of the Interfacial Exchange Interaction on the Metastability of Magnetic States of Core/Shell Nanoparticles

Abstract—Within the model of two-phase (core/shell) ellipsoidal nanoparticles, the effects of the interfacial exchange interaction, size, elongation, and orientation of the major axes of the core and shell on the metastability of magnetic states have been simulated. Using the example of ${{{\text{F}}{{{\text{e}}}_{3}}{{{\text{O}}}_{4}}} \mathord{\left/ {\vphantom {{{\text{F}}{{{\text{e}}}_{3}}{{{\text{O}}}_{4}}} {{\text{F}}{{{\text{e}}}_{{2.44}}}{\text{T}}{{{\text{i}}}_{{0.56}}}{{{\text{O}}}_{4}}}}} \right. \kern-0em} {{\text{F}}{{{\text{e}}}_{{2.44}}}{\text{T}}{{{\text{i}}}_{{0.56}}}{{{\text{O}}}_{4}}}}$ nanoparticles, it is shown that the metastability of magnetic states is realized in a limited range of the constant of interfacial exchange interaction between the core and shell, ${{A}_{{{\text{in}}}}}$, and geometric parameters. With an increase in the absolute value of the interfacial exchange interaction constant, $\left| {{{A}_{{{\text{in}}}}}} \right|$, from ${{A}_{{{\text{in}}}}} = 0$ to some finite value, the metastability of magnetic states decreases monotonically from maximum to zero, regardless of the angle between the major axes of the core and the shell.