1. μSR-Study of a 3% CoFe2O4 Nanoparticle Concentration Ferrofluid
- Author
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C. Stan, S. A. Kotov, A. L. Getalov, G. V. Scherbakov, M. Balasoiu, E. N. Komarov, K. I. Gritsaj, S. I. Vorob’ev, V. N. Duginov, and D. Buzatu
- Subjects
Phase transition ,Ferrofluid ,Materials science ,magnetoelectric interactions ,incommensurate magnetic structure ,Nanoparticle ,02 engineering and technology ,01 natural sciences ,Paramagnetism ,Magnetization ,muon ,0103 physical sciences ,Materials Chemistry ,QD1-999 ,010302 applied physics ,doped and nanostructured materials ,Condensed matter physics ,spin precession ,021001 nanoscience & nanotechnology ,Electronic, Optical and Magnetic Materials ,Magnetic field ,phase transitions ,Chemistry ,Chemistry (miscellaneous) ,Diamagnetism ,Magnetic nanoparticles ,0210 nano-technology - Abstract
Magnetic fluids based on single-domain magnetic spinel ferrite nanoparticles dispersed in various liquid media are of particular practical and scientific interest. This paper presents a muon spectroscopy study of a ferrofluid based on magnetic nanoparticles of CoFe2O4 molecules dispersed in water (H2O) with a nanoparticle concentration of 3%. In this study, it was determined that the structure and magnitude of the magnetization of a ferrofluid depend on the viscosity of the liquid itself. It was shown that, at room temperature (290 K) and under an external magnetic field of 527 G, the observed additional magnetization was ~20 G. In a small fraction of the sample under study (~20%), negative magnetization (diamagnetism) was observed. At low temperatures (~30 K), the sample acted as a paramagnet in a magnetic field. For the first time, the magnetic field inside and in the immediate vicinity of a CoFe2O4 nanoparticle has been measured experimentally using the μSR method: the value was 1.96 ± 0.44 kG, thus, direct measurement of the magnetization of a nanoscale object was performed.
- Published
- 2021