Comparative study of iron oxide nanoparticles as-prepared and dispersed in Copaiba oil using Mössbauer spectroscopy with low and high velocity resolution

Abstract

a b s t r a c tIron oxide nanoparticles, probably magnetite, as-prepared and dispersed in Copaiba oil were studied by Mössbauer spectroscopy using two different spectrometers: with a low velocity resolution (512 channels) for measurements at 295 and 21 K and with a high velocity resolution (4096 channels) for measurements at 295 and 90 K. The fitting of all measured spectra demonstrated that usual models applied to fit Möss-bauer spectra of magnetite and maghemite particles were not suitable. Therefore, the recorded spectra were fitted using a large number of spectral components on the basis of better quality of the fit and linearity of differential spectra. The number of components obtained for the better fit appeared to be different for spectra measured with a low and a high velocity resolution. However, these results demonstrated differences of Mössbauer parameters for iron oxide nanoparticles as-prepared and dispersed in Copaiba oil at applied temperatures. The effect of Copaiba oil molecules on Mössbauer parameters may be a result of the interactions of polar molecules such as kaurinic acid with nanoparticles' surface.

Study of Iron oxide nanoparticles using Mössbauer spectroscopy with a high velocity resolution

“…The EDS data recorded from our nominal samples lowering from 295 K down to low temperatures. Moreover, these spectra revealed asymmetrical six-line patterns with broad lines at 295 K and narrower lines at 90 and 21 K. As previously reported usual physical model accounting for the Iron cations at the tetrahedral (A) and octahedral [B] positions in magnetite cannot be used for a good spectra fit at the measured temperatures [16,17]. Therefore, as shown in Fig.…”

“…Copaiba oil dispersed in cyclohexane was then added to the as-produced ionic magnetic fluid under stirring. The resulting suspensions were dried to remove the solvent whereas the precipitated samples, namely the CO-treated magnetite (Fe 3 O 4 -CO) and the as-synthesized magnetite (Fe 3 O 4 ) nanoparticles were used for Mössbauer measurement [16]. Native maghemite nanoparticles (c-Fe 2 O 3 ) were prepared using the as-synthesized native magnetite nanoparticles as the starting material.…”

“…(see examples in [6][7][8][9]). Recently it was shown that Mössbauer spectroscopy with a high velocity resolution opened up new possibilities of this technique in the study of various Iron containing materials (see [10][11][12][13][14] Iron oxide nanoparticles using Mössbauer spectroscopy with a high velocity resolution showed new results [15][16][17][18]. In this study we review the results obtained from the study of magnetite, maghemite and mixed maghemite/magnetite nanoparticles developed for magnetic fluids using Mössbauer spectroscopy with a high velocity resolution.…”

Mössbauer spectroscopy with a high velocity resolution: Advances in biomedical, pharmaceutical, cosmochemical and nanotechnological research

“…Some iron oxide nanoparticles are used or developed for magnetic fluids for biomedical aims. A comparison of Mössbauer spectra of magnetite Fe 3 O 4 nanoparticles with the average size of 10 and 7 nm measured in [37,38] with a low velocity resolution and of 8 nm measured with a high velocity resolution (our results [39,40]) are shown in Fig. 8.…”

Magnetite nanoparticles as-prepared and dispersed in Copaiba oil: study using magnetic measurements and Mössbauer spectroscopy

“…Additionally, Mössbauer spectra were measured at 21 K in 512 channels using a conventional Wissel spectrometer with a low velocity resolution and a commercial cryostat (Oxford Instruments). The detailed characteristics of equipment, the data acquisition and their treatment are given elsewhere [3][4][5]. representative SEM, TEM and high-resolution TEM micrographs of the as-prepared Fe 3 O 4 nanoparticles are shown in Fig.…”