Multiscale magnetization in cobalt-doped ferrite nanocubes

J Appl Crystallogr. 2022 Dec 1;55(Pt 6):1622-1630. doi: 10.1107/S1600576722010287.

Abstract

The magnetization of cobalt ferrite nanocubes of similar size, but with varying Co/Fe ratio, is extensively characterized on atomistic and nanoscopic length scales. Combination of X-ray diffraction, Mössbauer spectroscopy, magnetization measurements and polarized small-angle neutron scattering (SANS) reveals that a lower amount of cobalt leads to an enhanced magnetization. At the same time, magnetic SANS confirms no or negligible near-surface spin disorder in these highly crystalline, homogeneously magnetized nanoparticles, resulting in an exceptionally hard magnetic material with high coercivity.

Keywords: Mössbauer spectroscopy; coercivity; ferrite; magnetic small-angle neutron scattering; nanoparticles; near-surface spin disorder.

Grants and funding

This work has been supported by Charles University Research Centre program No. UNCE/SCI/014. Financial support from the German Research Foundation (DFG grant No. DI 1788/2-1) is also gratefully acknowledged.