Tunable particle-agglomeration and magnetic coupling in bi-magnetic nanocomposites

Abstract

We propose an efficient way to synthesize strongly magnetically coupled nanocomposites, where the final extrinsic properties could be tuned by controlling the agglomeration of Co–Zn-ferrite nanoparticles in the Sr ferrite matrix and their elemental doping.

Chemical engineering of cationic distribution in spinel ferrite nanoparticles: the effect on the magnetic properties

“…S6, ESI †) shows a clear dependence: the average blocking temperature and temperature of M ZFC maximum (i.e., T b and T max ) decrease with an increase in Ni 2+ and Zn 2+ contents, suggesting a dominating effect of the magnetic anisotropy, even if an effect due to interparticle interactions can be present (ESI, † Section S6 and Table 2). 11…”

“…For these reasons, spinel ferrite nanoparticles (NPs) are suitable for many applications such as MRI contrast agents, [1][2][3] molecular detection and separation, drug delivery systems and hyperthermic therapy, 4,5 and design of rare-earth-free permanent magnets. [6][7][8][9][10][11] The spinel ferrite structure consists of a cubic close-packed (ccp) arrangement of oxygen atoms with tetrahedral (T d ) and octahedral [O h ] sites. [12][13][14] The cationic distribution is often reported as (M 1Àd 2+ Fe d…”

“…Ni 2+ tends to occupy the O h sites, while Zn 2+ prefers T d sites. 11,22,23 The selectivity for different sites leads to a change in the inversion degree of the spinel structure.…”

“…For these reasons, spinel ferrite nanoparticles (NPs) are suitable for many applications such as MRI contrast agents, 1–3 molecular detection and separation, drug delivery systems and hyperthermic therapy, 4,5 and design of rare-earth-free permanent magnets. 6–11…”