A comparative study of structural, electrical and magnetic properties of magnesium ferrite nanoparticles synthesised by sol-gel and co-precipitation techniques

Abstract

A comparative study of structural, electrical and magnetic properties of magnesium ferrite nanoparticles synthesised by sol-gel and co-precipitation techniques, Journal of Experimental Nanoscience, 8:3, 347-357, DOI: 10.1080/17458080.2012 Nano-sized magnesium ferrite was synthesised using co-precipitation and sol-gel techniques. Structural characterisation was performed using X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectrometer and scanning electron microscope. XRD analysis reveals the prepared samples are single phasic without any impurity. Particle size calculation shows that the crystallite size of sol-gel prepared samples is 9 nm and co-precipitation sample is 11 nm. FTIR analysis confirmed spinel structure of the prepared samples. Magnetic measurements show that both the samples are ferromagnetic with a high degree of isotropy in co-precipitation derived sample. The frequency dependence of the dielectric constant in the range 100 Hz-20 MHz was also investigated in the temperature range 303-533 K. The results of both the samples followed Maxwell-Wagner model based on interfacial polarisation in consonance with Koops theory.Keywords: nano-structured materials; magnesium ferrite; sol-gel technique; co-precipitation; magnetic measurement; dielectric properties IntroductionDiverse practical applications of spinel ferrites of the type MFe 2 O 4 has attracted the attention of researchers for decades. Nano-sized magnetic ferrite particles exhibit unique properties, which enable their use in a wide range of applications such as high density recording, high frequency devices and magnetic refrigerators [1,2]. There are several methods for synthesising nano-sized spinel ferrites, such as co-precipitation, sol-gel, microemulsion, hydrothermal and reverse micelle method [3][4][5]. Magnesium ferrite is a typical spinel in which the cation distribution in the crystal lattice site is sensitive to heat treatment due to high diffusibility of Mg 2þ ions [6,7]. Magnesium ferrites are used as humidity sensors [8], catalysts [9] and also in magnetic and gas sensing applications [10,11]. When its crystallite size is below a certain value, MgFe 2 O 4 possesses unique superparamagnetic properties at room temperature and has promising potential for applications in transformers, ferrofluids and magnet cores of coils [12,13].

Specific loss power of magnetic nanoparticles (fluid) hyperthermia in non-adiabatic conditions

“…These findings are in very good agreement with reports found in the literature [27][28][29] . The results for the magnesium ferrite in turn are in quite-good concordance with ICSD-152468 and with findings previously reported by different groups [30][31][32][33] , presenting peaks located at 2θ ranging from 28 • to 80 • , which are associated with the (220), (311), ( 222), (400), (422), (511), (440), (620) and (533) planes of the MgFe 2 O 4 . For both compositions, the patterns raise fingerprints of phases having cubic symmetry and Fd:3m space group.…”

Cytotoxic Effect of Nanocrystalline MgFe2O4 Particles for Cancer Cure

“…The transmittance spectra of the sample calcined at 150 ∘ C for 24 h are presented in Figure 4. The band observed at 3446 cm −1 is due to the symmetric stretching vibrations of O-H groups and the bands at 1638 and 1121 cm −1 are attributed to the symmetric stretching vibrations of hydrogen-bonded surface water molecules [43], which indicate the absorbed or free water presence in the samples [44]. These vibrations confirm the fact that hydroxyl groups are still reserved in the samples and are not entirely removed even after the samples were calcined at 200 ∘ C [45].…”

Electromagnetic wave absorption performance of Ni doped Cu-ferrite nanocrystals

“…Figures 4(a) and (b) shows, έ and e variation respectively, with frequency for Ni x Cu 1−x Fe 2 O 4 . It was observed that έ increases with the increase of frequency and decreases with the increase of frequency, which may be linked to the conducting networks conceived within the nano-particles and electronic polarization [48][49][50]. According to Koop's theory, the decrease in έ for an increase in frequency can be expressed by considering the solid as composed of well-conducting grains that are separated by poor conducting grain boundaries [51].…”