Use of magnetic resonance to investigate magnetic fluids for transformers application

Resumo

Magnetic resonance (MR) was used to investigate two magnetic fluid (MF) samples containing nanosized (average 3 nm in diameter) iron oxide particles suspended in insulating mineral and vegetal oils. The MR spectra were analyzed using two Lorentzian-like components. Analysis of the temperature (T) dependence of the resonance field (HR) indicates that the lower-field (higher-field) resonance line accounts for monomers (chain-like units). The solid-liquid phase transition of the MF samples, taking place around the melting point of the insulating oil (solvent), is indicated by a cusp in the HR £ T curve, which is more pronounced for the lower-field resonance line component. This finding was associated to a higher reorientation of the monomer’s magnetic moment upon melting of the MF sample.

Descrição

Palavras-chave

Transformer, Magnetic fluid, Magnetic resonance, Nanoparticle, Trasformador, Fluido magnético, Resonancia magnética, Nanopartículas

Citação

LEITE, E.S. et al. Use of magnetic resonance to investigate magnetic fluids for transformers application. Revista Mexicana de Física, Coyoacán, v. 58, n. 2, p. 249-252, Dec. 2012.