Magnetic States of Nanoparticles with RKKY Interaction

Abstract

Conditions of phase transitions in systems of identical ferromagnetic spherical nanoparticles randomly distributed in metal nonmagnetic matrix and superlattices of small number of nanoparticles with the Ruderman-Kittel-Kasuya-Yosida interaction are researched. In the framework of the Ising model the behavior of superspins is well described with the random interaction field method. The alteration of the effective magnetic moment due to the change in volume affects the choice of the magnetic state of the system: ferromagnetic spin glass or antiferromagnetic spin glass. The ground state of superlattice depends on the distance between particles.

Phase Transitions in Magnets with Competing Exchange Interactions

“…The method of random fields of the exchange interaction, which was developed in [1][2][3][4], allows you to associate the possibility of phase transitions with the concentration of the "ferromagnetic" atoms and calculate the critical concentration.…”

Synthesis of Cu and Ce co-doped ZnO nanoparticles: crystallographic, optical, molecular, morphological and magnetic studies

“…The variations in the values of M s depend on various factors, such as the shape and size of nanostructures, their stoichiometric ratio, concentration of dopants, lattice parameters, etc. The ferromagnetic interaction mechanism mainly includes two effects: the Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism [28][29][30][31] and Bound Magnetic Polarons (BPM) formation [32]. RKKY is caused by the interaction of electronic spin of homogenously distributed dopant within the host materials whereas the formation of BMP is caused by the alignment of the spins in transition metal ions with those of weakly bound carriers (excitons within a polaron radius).…”