Novel scanning magnetic microscopy method for the characterization of magnetic nanoparticles

• Published in: Journal of magnetism and magnetic materials 2020-04, Vol.499, p.166300, Article 166300
• Main Authors: Araujo, Jefferson F.D.F., Tahir, Arsalani, Soudabeh, Freire, Fernando L., Mariotto, Gino, Cremona, Marco, Mendoza, Leonardo A.F., Luz-Lima, Cleanio, Zaman, Quaid, Del Rosso, Tommaso, Baffa, Oswaldo, Bruno, Antonio C.
• Format: Article
• Language: English
• Subjects: Chemical precipitation; Chemical synthesis; Co-precipitation; Iron oxide magnetic nanoparticles; Iron oxides; Laser ablation; Magnetic properties; Magnetic scanning microscope; Magnetization; Magnetization curves; Magnetometers; Microscopy; Nanoparticles; Organic chemistry; Pulsed laser ablation in liquid; Pulsed lasers; Scanning magnetic microscopy
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2019.166300

•A new method for the magnetic characterization of nanoparticles.•We investigate the magnetic and morphological properties of colloidal dispersions of iron oxide magnetic nanoparticles.•We used a nonstandard model for obtaining the nanoparticles magnetizations values. In this paper, a new method is presented for the magnetic characterization of nanoparticles that is especially suitable for samples with a low mass, on the order of tens of micrograms. We investigated the magnetic and morphological properties of the colloidal dispersions of iron oxide magnetic nanoparticles that were synthesized by two methods: chemical precipitation (co-precipitation) and pulsed laser ablation in liquid (PLA). We measured the stray field generated above the samples by scanning magnetic microscopy (SMM) and used a nonstandard model to obtain the magnetization of the nanoparticles. We assessed the performance of the method by comparing the magnetization curves with measurements obtained using commercial magnetometers. The errors in the saturation and remanent magnetization were found to be approximately ±0.18 Am2/kg and ±0.6Am2/kg, respectively. As the samples exhibited a superparamagnetic state, we also used the magnetization curves to estimate the average size of the synthesized nanoparticles, which were found to be consistent with the results obtained using other techniques.