scholarly journals Effect of Nb3+ Substitution on the Structural, Magnetic, and Optical Properties of Co0.5Ni0.5Fe2O4 Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 430 ◽  
Author(s):  
Munirah. Almessiere ◽  
Yassibe Slimani ◽  
Murat Sertkol ◽  
Muhammed Nawaz ◽  
Ali Sadaqat ◽  
...  

Co0.5Ni0.5NbxFe2−xO4 (0.00 ≤ x ≤ 0.10) nanoparticles (NPs) were prepared using the hydrothermal approach. The X-ray powder diffraction (XRD) pattern confirmed the formation of single-phase spinel ferrite. The crystallite size was found to range from 18 to 26 nm. The lattice parameters were found to increase with greater Niobium ion (Nb3+) concentration, caused by the variance in the ionic radii between the Nb3+ and Fe3+. Fourier transform infrared analysis also proved the existence of the spinal ferrite phase. The percent diffuse reflectance (%DR) analysis showed that the value of the band gap increased with growing Nb3+ content. Scanning electron microscopy and transmission electron microscopy revealed the cubic morphology. The magnetization analyses at both room (300 K, RT) and low (10 K) temperatures exhibited their ferromagnetic nature. The results showed that the Nb3+ substitution affected the magnetization data. We found that Saturation magnetization (Ms), Remanence (Mr), and the Magnetic moment ( n B ) decreased with increasing Nb3+. The squareness ratio (SQR) values at RT were found to be smaller than 0.5, which postulate a single domain nature with uniaxial anisotropy for all produced ferrites. However, different samples exhibited SQRs within 0.70 to 0.85 at 10 K, which suggests a magnetic multi-domain with cubic anisotropy at a low temperature. The obtained magnetic results were investigated in detail in relation to the structural and microstructural properties.

Separations ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Kollur Shiva Prasad ◽  
Shashanka K Prasad ◽  
Ravindra Veerapur ◽  
Ghada Lamraoui ◽  
Ashwini Prasad ◽  
...  

Herein we report the synthesis of zinc oxide nanoparticles (ZnONPs) using Withania somnifera root extract (WSE) as an effective chelating agent. The microscopic techniques viz., X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) were employed to analyze the as-obtained ZnONPs. The crystalline planes observed from the XRD pattern agrees with the hexagonal wurtzite structure of the as-prepared ZnONPs. The aggregations and agglomerations observed in the SEM images indicated that the size of the as-prepared ZnONPs was between 30 and 43 nm. The interplanar distance between the lattice fringes observed in the HRTEM image was found to be 0.253 nm, which is in good agreement with the (100) plane obtained in the XRD pattern. Furthermore, the anti-breast cancer cytotoxic evaluation was carried out using the MCF-7 cell line, and the results showed significant cytotoxic effects in a dose-dependent manner.


2015 ◽  
Vol 48 (3) ◽  
pp. 836-843 ◽  
Author(s):  
Oindrila Mondal ◽  
Manisha Pal ◽  
Ripandeep Singh ◽  
Debasis Sen ◽  
Subhasish Mazumder ◽  
...  

The effect of dopant size (ionic radius) on the crystal growth, structure and optical properties of nanocrystalline calcium titanate, CaTiO3(CTO), have been studied using small-angle neutron scattering. X-ray diffraction, along with high-resolution transmission electron microscopy, confirms the growth of pure nanocrystalline CTO. Rietveld analysis reveals that the difference of ionic radii between dopant and host ions induces strain within the lattice, which significantly affects the lattice parameters. The induced strain, due to the difference of ionic radii, causes the shrinkage of the optical band gap, which is manifested by the redshift of the absorbance band. Mesoscopic structural analysis using scattering techniques demonstrates that the ionic radius of the dopant influences the agglomeration behaviour and particle size. A high-resolution transmission electron microscopy study reconfirms the formation of pure highly crystalline CTO nanoparticles.


2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.


Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Yuelong Xu ◽  
Bin Ren ◽  
Ran Wang ◽  
Lihui Zhang ◽  
Tifeng Jiao ◽  
...  

In the present study, nanoscale rod-shaped manganese oxide (MnO) mixtures were successfully prepared from graphitic carbon nitride (C3N4) and potassium permanganate (KMnO4) through a hydrothermal method. The as-prepared MnO nanomixtures exhibited high activity in the adsorption and degradation of methylene blue (MB). The as-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Furthermore, the effects of the dose of MnO nanomixtures, pH of the solution, initial concentration of MB, and the temperature of MB removal in dye adsorption and degradation experiments was investigated. The degradation mechanism of MB upon treatment with MnO nanomixtures and H2O2 was studied and discussed. The results showed that a maximum adsorption capacity of 154 mg g−1 was obtained for a 60 mg L−1 MB solution at pH 9.0 and 25 °C, and the highest MB degradation ratio reached 99.8% under the following optimum conditions: 50 mL of MB solution (20 mg L−1) at room temperature and pH ≈ 8.0 with 7 mg of C, N-doped MnO and 0.5 mL of H2O2.


2010 ◽  
Vol 43 (5) ◽  
pp. 990-997 ◽  
Author(s):  
Jie Ma ◽  
Qingsheng Wu

A facile oxides–hydrothermal (O–HT) method is demonstrated to prepare high-purity monazite-type LaPO4nanomaterials. In this approach, La2O3and P2O5powder are first directly used as precursors under additive-free hydrothermal conditions. The as-prepared samples are characterized with X-ray diffraction, Fourier transform IR spectroscopy, thermogravimetry, scanning electron microscopy, transmission electron microscopy (high-resolution TEM, energy dispersive spectroscopy) and selected-area electron diffraction. The typical sample obtained at 433 K in 24 h comprises uniform single-crystal nanofibres with a diameter of ∼15–28 nm and an aspect ratio of 30–50. The influences of treatment time, synthesis temperature and P/La molar ratio are investigated. The phase transition from hexagonal hydrate to monoclinic anhydrous lanthanum phosphate and the growth process of nanofibres are revealed by the experimental results. The formation mechanism of the monoclinic LaPO4is discussed. The result indicates that the P/La ratio does not influence the composition and crystal phase but changes the morphology of the product in the O–HT system.


2015 ◽  
Vol 27 (23) ◽  
pp. 8146-8152 ◽  
Author(s):  
Wen-I Liang ◽  
Xiaowei Zhang ◽  
Karen Bustillo ◽  
Chung-Hua Chiu ◽  
Wen-Wei Wu ◽  
...  

1997 ◽  
Vol 3 (S2) ◽  
pp. 521-522
Author(s):  
A.F. Marshall ◽  
L. Klein ◽  
J.S. Dodge ◽  
C.H. Ahn ◽  
J.W. Reiner ◽  
...  

SrRuO3 is a low temperature ferromagnet (Tc ≌ 150K) which has recently been investigated in thin film form due to its structural compatibility with other thin film perovskites materials of practical interest, including high-temperature superconductors. Magnetization studies of thin films of SrRuO3 deposited on cubic SrTiO3 indicate strong uniaxial anisotropy with the easy direction approximately along either the a or b axis, which are difficult to distinguish. The orthorhombic structure of SrRuO3 (a = 5.53, b = 5.57, c = 7.84 Å) has six symmetry-related orientations on the cubic substrate (a = 3.9Å). Using Lorentz transmission electron microscopy both the magnetic and the crystallographic domain microstructure are characterized.For TEM imaging the films are readily removed from the substrate by chemical etching, using a HF:HNO3:H2O etch of approximately 1:1:1 dilution. Free-floating SrRuO3 films of 300-1000Å in thickness are then supported on standard carbon/formvar films on Cu substrates.


2016 ◽  
Vol 35 (6) ◽  
pp. 559-566 ◽  
Author(s):  
Elaheh Esmaeili ◽  
Mohammad Sabet ◽  
Masoud Salavati-Niasari ◽  
Kamal Saberyan

AbstractPbS nanostructures were synthesized successfully via hydrothermal approach with a new precursor. The products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Vis diffuse reflectance spectroscopy (DRS). The effect of different sulfur sources were investigated on product size and morphology.


2016 ◽  
Vol 13 (10) ◽  
pp. 7408-7415
Author(s):  
Yongxing Li ◽  
Qiong Xiao ◽  
Qin Yin ◽  
Hui Ni ◽  
Yanbing Zhu ◽  
...  

Arylsulfatase, one of a few enzymes that can enhance the gelling strength of agar by cleaving the sulfate ester bonds in agar, was covalently immobilized with carboxyl functioned magnetic nanoparticles (CMNPs). The resultant CMNPs and immobilized arylsulfatase were characterized by transmission electron microscopy (TEM), Dynamic Light scattering (DLS), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). The TEM result indicated that the CMNPs and immobilized arylsulfatase had a similar mean particle size of 10 nm. The arylsulfatase-CMNPs had a mean diameter of 1200 nm in aqueous solution determined by the DLS, which was much bigger than the CMNPs (433.6 nm). The different sizes demonstrated that the arylsulfatase was coated on CMNPs successfully. XRD showed that diffraction patterns of the CMNPs and arylsulfatase-CMNPs were close to the standard XRD pattern of Fe3O4. Saturation magnetizations were 52.1 emu/g for carriers and 47.9 emu/g for immobilized arylsulfatase, which indicated that the particles had superparamagnetic characteristics. The TGA revealed that the amount of arylsulfatase bound to the surface of CMNPs was 5.65%. The arylsulfatase exhibited better thermal stability and reusability after immobilization, the immobilized arylsulfatase can retain more than 50% enzyme activity up to the 9th cycle.


2017 ◽  
Vol 32 (S1) ◽  
pp. S193-S200
Author(s):  
B. Peplinski ◽  
B. Adamczyk ◽  
P. Formanek ◽  
C. Meyer ◽  
O. Krüger ◽  
...  

This paper reports the first successful synthesis and the structural characterization of nanocrystalline and stacking-disordered β-cristobalite AlPO4 that is chemically stabilized down to room temperature and free of crystalline impurity phases. Several batches of the title compound were synthesized and thoroughly characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy mapping in SEM, solid-state 31P nuclear magnetic resonance (31P-NMR) spectroscopy including the TRAPDOR method, differential thermal analysis (DTA), gas-sorption methods, optical emission spectroscopy, X-ray fluorescence spectroscopy, and ion chromatography. Parameters that are critical for the synthesis were identified and optimized. The synthesis procedure yields reproducible results and is well documented. A high-quality XRD pattern of the title compound is presented, which was collected with monochromatic copper radiation at room temperature in a wide 2θ range of 5°–100°.


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