Evaluation of Nanoparticle-size distribution with Mössbauer Effect spectroscopy

MELE, NICOLÁS G.; ARRIETA GAMARRA, DIANA I.; MENDOZA ZÉLIS, PEDRO; SÁNCHEZ, FRANCISCO H.; PASQUEVICH, GUSTAVO A.

HYPERFINE INTERACTIONS

Springer

Año: 2022 vol. 243

0304-3843

The Mössbauer effect (ME) spectroscopy is a powerful tool to obtain information about magnetic nanoparticles (NP). Here we correlate parameters that can be obtained from a ME spectrum (relative fractions of magnetite and maghemite and the volume dependent parameter 𝜆=𝐾𝑉/𝑘𝐵𝑇) with other relevant quantities, such as DC saturation magnetization and X-ray diffraction NP mean diameter, DXRD. The study was performed on the decanted pellets of six different batches of NP obtained using the same synthesis procedure. It was observed that 𝜆1/3 presents a linear correlation with DXRD from which the effective anisotropy K for the entire ensemble of the batches could be calculated. The fraction of magnetite retrieved from ME spectra was well correlated to the saturation magnetization. In addition, it was observed that the magnetic response of the supernatant obtained after washing and centrifuging the synthesis product, decreases with 𝜆, according to the fact that larger NP decant more easily during centrifugation.