Kalpana M Angadi,1 Vivekanand B Jadhav,2 Savita V Jadhav1 1Symbiosis Medical College for Women (SMCW) & Symbiosis University Hospital and Research Centre (SUHRC), Symbiosis International (Deemed ...University), Pune, India; 2Dr. Naidu Infectious Diseases Hospital, Pune Municipal Corporation Pune Maharashtra, Pune, India Correspondence: Savita V Jadhav, Email email protected View the original paper by Mr Alelign and colleagues
Magnetic nanofluids (commonly known as ferrofluids) have captured the great attention of the researchers due to their various kinds of applications such as heat transfer, hyperthermia treatments, ...targeted drug delivery etc. The present experimental investigations deal with the thermoacoustic behaviour of the water based nanofluids of nickel ferrites. The magnetic nickel ferrite nanoparticles were produced by the simple and inexpensive chemical co-precipitation route. The prepared nanoparticles were exposed to different characterization tools for structural, morphological, compositional and magnetic properties analysis. X-ray diffraction analysis with Rietveld refinement confirmed the single phasic nature with nanometric crystallite size of the prepared nanoparticles. Scanning electron microscope images revealed the spherical and nanocrystalline morphology of the prepared nanoparticles. The M-H plot recorded at room temperature revealed the superparamagnetic nature of the nanoparticles. Further, the co-precipitated nickel ferrite nanoparticles with different concentrations were utilized for the preparation of the water based magnetic nanofluids. Colloidal stability of the prepared nanofluids was analyzed by UV–Vis spectroscopy technique and it revealed the stability over 11 days without separation in phase. The temperature dependent thermoacoustic properties of the prepared nanofluids were analyzed through Ultrasonic Interferometer. The interaction between particle–particle and particle–fluid are explained on the basis of thermo-acoustic parameters.
A profoundly effective magnetically recoverable nano zinc ferrite nanocatalyst was fabricated by means of sol-gel auto ignition strategy. The synthesized nanocatalyst has been completely portrayed by ...standard techniques for structural, morphological, compositional, surface, magnetic, dielectric, optical and photoluminescence properties individually. The x-ray diffraction pattern affirmed the arrangement of cubic spinel structure with an average crystallite size of 21 nm. FE-SEM images uncovered the circular morphology with nanometric average grain measure (37 nm). The surface area, pore volume and pore radius was observed to be 39.812 m2 g−1, 3.41 cc g−1 and 1.34 nm individually from BET analysis. VSM investigation demonstrated the superparamgnetic nature of the prepared sample with moderate magnetization value and negligible coercivity. The optical band gap deduced from UV-vis spectra was observed to be 2.098 eV. Every one of these properties of zinc nanoferrite makes them brilliant contender for microwave radiation absorption. Further, a proficient and versatile microwave irradiated solvent free synthesis of chalcone derivatives has been developed using prepared zinc nanoferrite catalyst. The remarkable highlights of this new protocol are solvent free reaction, economical cheapness, eco-friendliness, high yields, reduced reaction times and easy recovery and reuse of zinc ferrite nanocatalyst.
Cobalt ferrite thin films with magnesium substitution (Co1-xMgxFe2O4 for 0.0 ≤ x ≤ 1.0) were grown on clean glass substrate with dimensions (75 mm × 25 mm × 1.45 mm) using spray pyrolysis method. The ...grown thin films were annealed at 500 °C for 4 h and further used for structural, morphological, optical and surface wettability investigations. The structural characterizations of the prepared films were performed through X-ray diffraction (XRD) technique at room temperature. The analysis of the XRD pattern shows the formation of single phase cubic spinel structure of the films. The most intense peak (311) of the XRD pattern was used to estimate the average crystallite size. The obtained crystallite size varies between 16 nm and 19 nm confirming the nanocrystalline nature of the films. The lattice constant calculated from XRD data show decreasing nature from 8.386 Å to 8.365 Å with increase in magnesium content x. The variation of X-ray density with magnesium content x shows initial increasing nature and then decreasing nature. Metal cation active vibration modes, metal oxygen stretching and bending vibrations were confirmed through the Raman analysis. Surface morphology of the films was studied by using scanning and transmission electron microscopy (SEM and TEM) technique. Observations of SEM micrographs reveal that particles are in nanosize dimensions and almost distributed uniformly. Particle size calculated from TEM analysis was found to be in the range of 5–18 nm. The band gap of the films was measured by UV-VIS spectrophotometer. It is observed that, the energy band gap decrease from 2.83 eV to 2.37 eV as increase in magnesium substitution. The Photoluminescence study showed the characteristic near-band-edge emission of presently investigated films samples at around 710 nm. The contact angle measurements revealed the hydrophilic nature of all the thin films under investigation.
•Successful deposition of Mg2+ substituted CoFe2O4 thin films on glass substrates by spray pyrolysis technique.•Structural, morphological, compositional, optical and wettability properties were explored.•SEM and TEM analysis confirmed the nanocrystalline nature of all the thin films under investigations.•SEM and TEM analysis confirmed the nanocrystalline nature of all the thin films under investigations.
In the vision of hyperthermia application, high quality superparamagnetic MnFe2O4 nanoparticles (NPs) were synthesized via low cost and environment-friendly co-precipitation method. Thermogravimetric ...and differential thermal analysis studies confirmed the ferritization temperature at 900 °C. The formation of crystals with a single-phase cubic spinel structure with the Fd3m space group has been confirmed by XRD analysis. SEM-EDX result reveals that the spherical nature of grains with some agglomeration and elemental analysis helps to calculate the atomic percentage of each detected element. An average particle size (~25 nm) was determined by TEM analysis. VSM analysis shows that saturation magnetization (Ms) increases with decreasing temperature in the range 54.18–59.67emu/g at room temperature (300K) to low temperature (5K), respectively, which displays temperature change affects the saturation magnetization and coercivity. FC-ZFC measurements indicated a blocking temperature of NPs around 97.17K. The induction heating study was performed on MnFe2O4 magnetic NPs at 4 kA/m AC magnetic field amplitude and 280 kHz frequency for application in magnetic hyperthermia. The result demonstrates that the heating ability of MnFe2O4 magnetic NPs can be achieved hyperthermia temperature (42 °C) at small content of 0.4 g/mL within 260sec-time duration, which confirms that the prepared material can be used as a heating agent in magnetic hyperthermic treatment. The specific absorption rate (SAR) was found at 217.62 W/g, the obtained result is superior to the previous reports. The obtained results show that the newly synthesized superparamagnetic NPs can act as a promising candidate for hyperthermia therapy due to its high heat-generating capability at lower concentrations with less time period.
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The present work reports the structural, thermal, spectral, optical and surface analysis of rare earth metal ion (Gd3+) doped mixed Zn–Mg nano-spinel ferrites. The samples of Gd3+ doped Zn–Mg nano ...ferrites with equi-amount chemical composition i.e. Zn0.5Mg0.5Fe2-xGdxO4 (0.00 ≤ x ≤ 0.10 in step of 0.02) were prepared by self-ignited sol-gel route. The variance in the thermal behaviour and spinel phase development with weight loss percentage in the prepared samples was investigated by TG-DTA technique. The powder X-ray diffraction (P-XRD) patterns ensured the nanocrystalline mono-phasic formation and spinel-cubic structure of all the samples. The trend of increment in lattice constant (a) and decrement in crystallite (t) size was observed with the doping of Gd3+ ions. The appearance of two requisite vibrational stretching modes was affirmed by the FT-IR spectral studies. The UV–Vis optical analysis displayed the augmentation in absorbance and drastic decrement in energy band gap value (1.96 eV–1.83 eV) with Gd3+ doping. The photo-luminescent (PL) studies revealed the broad near band-edge emission in visible wavelength range (523 nm–528 nm) for all the samples. The surface parameters investigation was undertaken with the help of BET isotherms recorded by the N2-physisorption and BJH model. The various surface parameters such as BET surface area, volume and radius of the pores, distribution of the pore sizes etc were construed from the BET data. The enhancement in these surface parameters via Gd3+ doping was noted for all the samples. The outcomes of the present work reflects the influential doping of Gd3+ ions in Zn–Mg nano ferrites, which can be implementable for bio-applications as thermal seeds in magnetic hyperthermia or as contrast enhancer in medical MRI imaging.
Zn
2+
-substituted cobalt ferrites (Co-ferrite) having the chemical formula Co
1−
x
Zn
x
Fe
2
O
4
(
x
= 0.0, 0.5 and 1.0) were fabricated by a co-precipitated wet chemical route. The analysis of ...weight loss percentage with spinel phase development and evaluation of sintering temperature of prepared samples were studied by applying the TG–DTA technique. Structurally refined XRD patterns of the prepared samples revealed the phase purity and cubic spinel structure with the Fd-3m space group. The fractional atomic positions and Rietveld refinement factors were estimated from Rietveld refined XRD pattern, and also, other variations of structural parameters with zinc substitution have been calculated from XRD data. Both the Rietveld refinement and W–H method were employed to calculate the crystallite size, and both of them presented the same calculated result. The variation in the shape of particles and average particle size with Zn
2+
substitution in Co-ferrite was evaluated from the FE-SEM technique. The formation of cubic spinel structure and change in the modes of vibrations with respect to Zn concentration in Co-ferrite of all samples were observed from the best peak-fitted Raman spectra. All the magnetic properties decreased with increasing concentration of zinc investigated from M–H loops which were obtained with the application of the VSM technique. ZFC–FC curve reveals that the blocking temperature of Co-ferrite samples decreases with increasing Zn concentration. It is possible to modulate or adjust the magnetic properties of Co-ferrite nanoparticles by Zn
2+
doping as a favorable material for biomedical applications such as drug delivery, magnetic hyperthermia and magnetic resonance imaging (MRI).
Monodispersed Mn
0.5
Zn
0.5
Fe
2
O
4
(~ 14 nm) nanoparticles were prepared by using a chemical co-precipitation technique. The direct mixing method has been used to prepare ferrofluid (base ...fluid-water) and to investigate their properties for the application of magnetic hyperthermia. Phase identification, crystal structure, and average crystallite size of the prepared samples were revealed in the XRD analysis. It confirms the Fd3m space group cubic spinel structure and average crystallite size ~ 14 nm. From TEM evaluation, the average particle size was found at ~ 16 nm. The 41.12 emu/g magnetization value of the Manganese Zinc Ferrite (MZF) nanoparticles (NPs) was found at room temperature. A negligible coercivity and remanence values confirm the superparamagnetic behavior of MZF nanoparticles at room temperature were confirmed by vibrating sample magnetometer (VSM) analysis. The induction heating analysis on water dispersed MZF Magnetic NPs at 4 kA/m AC magnetic field amplitude and 280 kHz frequency was conducted to use them in the application of hyperthermia. The result specifies that the heating potential of prepared ferrofluids can be reached within 65 s of hyperthermia temperature (42 °C) at lower 4 mg/mL content, indicating that the prepared material can be used as a heating agent for the treatment of magnetic hyperthermia. The specific absorption rate (SAR) was found to be 110.90 W/g. Thus, the obtained results suggest that the prepared MZF nanoparticles are a promising candidate for hyperthermia therapy due to their high heat-generating ability with less time at a lower concentration.
A series of ferrite with a chemical composition Co0.7Zn0.3GdxFe2−xO4 (where x=0.0 to x=0.1) were prepared by sol-gel auto-combustion method. X-ray diffraction pattern were used to determine the ...crystal structure and phase formation of the prepared samples. Scanning electron microscopy is used to study the surface morphology of the prepared samples. Elastic properties were determined from the infrared spectroscopy. Debye temperature, wave velocities, elastic constants found to increase with the increase in Gd3+ substitution. Dielectric properties such as dielectric constant and dielectric loss were studied as a function of Gd3+ substitution and frequency. Dielectric constant decreased with the increase in frequency and Gd3+ substitution. Behavior of dielectric properties was explained on the basis of Maxwell-Wagner interfacial polarization which in accordance with Koops phenomenological theory. Real and imaginary part of impedance was studied as a function of resistance and Gd3+ substitution. The behavior of impedance is systematically discussed on the basis of resistance-capacitance circuit.
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