Magnetic Response of NiFe2O4 nanoparticles in polymer matrix

TL;DR

This study investigates how varying amounts of NiFe2O4 nanoparticles in a polymer matrix affect the composite's magnetic properties, revealing temperature-dependent magnetic behaviors influenced by particle interactions and surface effects.

Contribution

It provides new insights into the magnetic behavior of NiFe2O4-polymer nanocomposites, emphasizing the role of particle quantity and inter-particle interactions.

Findings

Lower particle quantities show magnetization upturn at low temperatures.

Higher particle quantities exhibit dominant magnetization blocking at low temperatures.

Magnetic behavior is explained by core-surface spin competition and dipole interactions.

Abstract

We report the magnetic properties of magnetic nano-composite, consisting of different quantity of NiFe2O4 nanoparticles in polymer matrix. The nanoparticles exhibited a typical magnetization blocking, which is sensitive on the variation of magnetic field, mode of zero field cooled/field cooled experiments and particle quantity in the matrix. The samples with lower particle quantity showed an upturn of magnetization down to 5 K, whereas the blocking of magnetization dominates at lower temperatures as the particle quantity increases in the polymer. We examine such magnetic behaviour in terms of the competitive magnetic ordering between core and surface spins of nanoparticles, taking into account the effect of inter-particle (dipole-dipole) interactions on nanoparticle magnetic dynamics.