Effect of bimetallic (Ni and Co) substitution on magnetic properties of MnFe2O4 nanoparticles

Nickel and cobalt substituted manganese ferrite nanoparticles (NPs) with the chemical composition NixCoxMn1–2xFe2O4 (0.0?x?0.5) NPs were synthesized by one-pot microwave combustion route. The effect of co-substitution (Ni, Co) on structural, morphological and magnetic properties of MnFe2O4 NPs was investigated using XRD, FT-IR, SEM, VSM and Mössbauer spectroscopic techniques. The cation distribution of all products were also calculated. Both XRD and FT-IR analyses confirmed the synthesis of single phase spinel cubic product for all the substitutions. Lattice constant decreases with the increase in concentration of both Co and Ni in the products. From 57Fe Mössbauer spectroscopy data, the variations in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values with Mn2+, Ni2+ and Co2+ substitution have been determined. While the Mössbauer spectra collected at room temperature for the all samples are composed of magnetic sextets, the superparamagnetic doublet is also formed for MnFe2O4 and Ni0.2Co0.2Mn0.6Fe2O4 NPs. The magnetization and Mössbauer measurements verify that MnFe2O4 and Ni0.2Co0.2Mn0.6Fe2O4 NPs have superparamagnetic character. The saturation and remanence magnetizations, magnetic moment and coercive field were determined for all the samples. Room temperature VSM measurements reveals saturation magnetization value close to the bulk one. It has been observed that the saturation magnetization and coercive field increase with respect to the Ni and Co concentrations. © 2016 Elsevier Ltd and Techna Group S.r.l

Sonochemical synthesis of Eu3+ substituted CoFe2O4 nanoparticles and their structural, optical and magnetic properties

PubMedID: 31450366Magnetic, optic and microstructural properties of ultrasonically synthesized CoEuxFe2-xO4 (x ? 0.1)nanoferrites (NFs)have been examined in this study. After sonochemical synthesis, XRD and FT-IR analyses confirmed the purity, the structure (cubic spinel structure and Fd3m space group)and the spectral properties of the spinel ferrite samples. The spherical morphology and chemical compositions of the products were observed via transmission and scanning electron microscopes along with EDX and elemental mapping. Percent diffuse reflectance (%DR)was used for optical investigation. Optical band gaps (Eg)were estimated utilizing Kubelka-Munk theory and Tauc equation. Eg values are in a narrow band of 1.34 to 1.44 eV. The magnetic parameters like Ms (saturation magnetization), SQR = Mr/Ms (squareness ratio), nB (magnetic moment), Hc (coercivity)and Mr (remanence)have been evaluated by analyzing measurements of magnetization versus magnetic field performed at room (RT; T = 300 K)and low (T = 10 K)temperatures. It is showed that the different produced CoEuxFe2-xO4 (0.00 ? x ? 0.10)nanospinel ferrites present superparamagnetic (SPM)nature at RT. At low temperature, the various produced CoEuxFe2-xO4 (x ? 0.08)nanospinel ferrites display ferrimagnetic (FM)nature. With exception, the x = 0.10 sample exhibit SPM behavior at T = 10 K. It is noticed that the Eu3+ substitutions alter in a significant way on the magnetic data. A decreasing trend in the Ms, Mr and nB values was noted with Eu3+ substitutions. © 2019 Elsevier B.V

Structural, magnetic, optical properties and cation distribution of nanosized Ni0.3Cu0.3Zn0.4TmxFe2-xO4 (0.0???x???0.10) spinel ferrites synthesized by ultrasound irradiation

PubMedID: 31085087In this study, Tm3+ ion substituted NiCuZn nanospinel ferrites, Ni0.3Cu0.3Zn0.4TmxFe2-xO4 (0.0 ? x ? 0.10), have been synthesized sonochemically. The structural, spectroscopic, morphological, optic and magnetic investigation of the samples were done by X-ray powder diffractometry (XRD), Fourier transform infrared spectrophotometry (FT-IR), UV–Vis diffused reflectance (%DR) spectrophotometry, transmission and scanning electron microscopies (TEM and SEM) along with EDX, Vibrating sample magnetometry (VSM), respectively. The purity of prepared products were confirmed via XRD, FT-IR, EDX and elemental mapping analyses. The analyses of magnetization versus M(H) (applied magnetic field) were performed at 300 and 10 K. The following magnetic parameters like Ms (saturation magnetization), SQR = Mr/Ms (squareness ratio), nB(magnetic moment), Hc (coercivity) and Mr (remanence) have been discussed. M(H) loops revealed superparamagnetic property at RT and soft ferromagnetic nature at 10 K. It is showed that the Tm3+ substitutions significantly affect the magnetizations data. A decreasing trend in the Ms, Hc, Mr, and nB values was detected with Tm3+ substitution. © 2019 Elsevier B.V.2019-IRMC-S-1, 2017-IRMC-S-3, 2018-IRMC-S-2 Deanship of Scientific Research, King Faisal University: 2018-209-IRMC Islamic Azad UniversityThe authors appreciate the support of the Institute for Research & Medical Consultations (Projects No. 2019-IRMC-S-1, No. 2018-IRMC-S-2 and No. 2017-IRMC-S-3) and Deanship for Scientific Research (Project No. 2018-209-IRMC) of Imam Abdulrahman Bin Faisal University (IAU – Saudi Arabia)