Synthesis of nanoparticles of feroxyhyte doped with lanthanum by a sonochemical method
Year: 2025
Type: article
Abstract: • In this work, a new sonochemical synthetic method for the formation of La-doped feroxyhyte is shown. • The results of this work have promising potential since, to date, no synthesis method showing the formation of La-doped feroxyhite has been proposed. • The presence of lanthanum is necessary in the initial moments of the synthesis to prevent the system from evolving into magnetite. • This method allows to modulate the amount of lanthanum contained in the sample. • A potentially useful system as a bimodal contrast agent in both resonance and X-ray techniques has been synthesized. This work deals with the sonochemical synthesis of colloidal dispersions of magnetic nanoparticles formed by lanthanum-doped iron oxyhydroxides coated with citrate. Our aim is to obtain bimodal contrast agents with magnetic properties that allow their use in both resonance and X-ray techniques. For this purpose, three synthesis strategies have been developed using a combination of ultrasound and co-precipitation methods. Three ultrasound frequencies were used in the synthesis: 581, 861 or 1141 kHz. The structural characterization of the prepared materials was carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, total reflection X-ray fluorescence (TXRF) and Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDX) In the presence of lanthanum, magnetite cannot be formed. Instead, an orange-brown magnetic compound is obtained. Both XRD diffraction patterns and Raman spectra confirmed that the obtained compound is a feroxyhyte containing an amorphous lanthanum compound in its structure. The size of the feroxyhyte nano-discs remained almost constant when the ultrasound frequency was increased. The La/Fe molar ratio of the samples obtained increases when La(OH) 3 , which is prepared in the preliminary stages, is added rather than LaCl 3 . This procedure makes it possible to control the amount of lanthanum absorbed by the sample by simply varying its initial concentration.
Source: Ultrasonics Sonochemistry
Authors: Dolores Reyman, Cristina Díaz-Oliva
Institution: Universidad Autónoma de Madrid
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,710
Award: G453362481
OpenAlex ID: W4409616725