scholarly journals Solvothermal Synthesis and Magnetic Properties of Monodisperse Ni0.5Zn0.5Fe2O4 Hollow Nanospheres

2019 ◽  
Vol 38 (2019) ◽  
pp. 76-83 ◽  
Author(s):  
Min Zhang ◽  
Qiangchun Liu

AbstractThe monodisperse Ni0.5Zn0.5Fe2O4 nanospheres have been synthesized via a simple solvothermal method. The effects of reactant concentration on structural and magnetic properties have been studied. X-ray diffraction analysis results indicate that the lattice constant and crystallite size can be tuned by controlling reactant concentration. The nanosphere size monotonically decreases from 238 to 35 nm with increasing reactant concentration. The magnetic studies show that blocking temperature is enhanced, and these single-domain particles are superparamagnetism at room temperature. The hollow nanospheres exhibit a high saturation magnetization value of 52.6 emu/g. The nanospheres with various diameters exhibit different magnetic saturation values which may be caused by the domain structure, surface effects and the distribution of metal ions on A and B sites. These superparamagnetic Ni0.5Zn0.5Fe2O4 nanospheres are expected to have potential application in biomedicine and magnetic fluid technology.

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Yan Xu ◽  
Yantian Liang ◽  
Lijuan Jiang ◽  
Huarui Wu ◽  
Hongzhi Zhao ◽  
...  

Ordered ZnFe2O4nanotube arrays with the average outer diameter of 100 nm were prepared in porous anodic aluminum oxide template using an improved sol-gel approach. The morphology was studied by transmission electron and field emission scanning electron microscope. X-ray diffraction result shows that the nanotubes were polycrystalline in structure. The magnetic properties of the prepared ZnFe2O4nanotubes were also studied. The results show that the sample shows typical superparamagnetism at room temperature and obvious ferromagnetism below blocking temperature.


2012 ◽  
Vol 29 (1) ◽  
pp. 50
Author(s):  
D.N Ba ◽  
L.T Tai ◽  
N.T Trung ◽  
N.T Huy

The influences of the substitution of Ni with Mg on crystallographic and magnetic properties of the intermetallic alloys LaNi5-xMgx (x ≤ 0.4) were investigated. The X-ray diffraction patterns showed that all samples were of single phase, and the lattice parameters, a and c, decreased slightly upon chemical doping. LaNi5 is well known as an exchange-enhanced Pauli paramagnet. Interestingly, in LaNi5-xMgx, the ferromagnetic order existed even with a small amount of dopants; the Curie temperature reached the value of room temperature for x = 0.2, and enhanced with increasing x.


2012 ◽  
Vol 535-537 ◽  
pp. 950-953
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Zhi Jian Duan ◽  
Jian Jun Zhang

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It is Observed through the experiment: the addition of Gd enhances martensite transition temperature;X-ray diffraction analysis of experimental alloys is revealed that to the mixture is martensite and austenite at room temperature; content of Gd is not proportional to the improvement of magnetic property.


2011 ◽  
Vol 335-336 ◽  
pp. 934-939
Author(s):  
Z. F. Zi ◽  
Y. N. Liu ◽  
Q.C. Liu ◽  
Jian Ming Dai ◽  
Yu Ping Sun

Magnetite (Fe3O4) nanobranches were synthesized using an improved solvothermal technique in mixed ethanol and water solvent. Structural and magnetic properties were systematically investigated. X-ray diffraction results showed that the sample was single-phase spinel structure. The results of scanning electronic microscopy exhibited that the grains were regular like-branch with sizes from 3 to 6 μm in length and in diameter between 50 and 200 nm. The composition determined by energy dispersive spectroscopy was very close to the stoichiometry of Fe3O4. The saturation magnetizations (Ms) at 10 and 300 K of the synthesized Fe3O4nanobranches were much lower than the theoretical values. On one hand, it could be explained by obstructive magnetizing along their non-easy magnetic axes by the shape anisotropy of Fe3O4nanobranches, on the other hand, lesserMscan also be understood by the existence of antisite defects.


2014 ◽  
Vol 92 (5) ◽  
pp. 389-394 ◽  
Author(s):  
S.F. Mansour ◽  
N.I. Abu-Elsaad ◽  
T.A. Elmosalami

Bi1–xCaxFeO3 was prepared by the flash autocombustion combustion technique. X-ray diffraction analysis showed a Rhombohedrally distorted hexagonal perovskite structure with space group R3c. The particle size and shape were studied by transmission electron microscope. Magnetization studies at room temperature showed superparamagnetic behavior for the prepared nanoparticles. Magnetoelectric coefficient characterized as magnetic field – induced polarization was investigated. The Lande factor (g), resonance field (Br), relaxation time (τ), and the energy between two adjacent degenerate spin energy levels (ΔE) were estimated from the electron spin resonance spectra.


2004 ◽  
Vol 818 ◽  
Author(s):  
Yanglong Hou ◽  
Hiroshi Kondoh ◽  
Toshiaki Ohta

AbstractThe combination of 1-adamantanecarboxylic acid and tri-alkylphosphine was applied to produce monodisperse FePd nanoparticles by the polyol reduction of palladium acetylacetonate and thermally decomposition of iron pentacarbonyl. Images of high resolution transmission electron microscopy (TEM) and X-ray diffraction (XRD) data indicate a highly monodisperse and crystalline nature of the FePd nanoparticles. Magnetic studies performed by Quantum Design SQUID magnetometer show that FePd (16nm) nanoparticles are superparamagnetic at room temperature.


2019 ◽  
Vol 3 (2) ◽  
pp. 53-57
Author(s):  
Mohammed Abdul Malek Al Saadi

Barium hexaferrite (BHF) (BaFe12O19) and its substituted derivatives have been considered as the most potential magnetic candidates with considerable chemical stability and physiochemical characteristics. BHF with x ferrite ions substituted by titanium (Ti-doped BTHF) (BaTixFe12-xO19) (x=1 and x=3) was prepared from ferric oxide (Fe2O3), barium oxide (BaO), and titanium oxide (TiO2) of purity >98%. The materials were mixed with deionized water and then dried at 1100°C and 1200°C overnight. For the formation of BaFe12O19 phase, the mixture was annealed at a rate of 10°C/min in static air atmosphere until reaching 1200°C and then maintained for 10 h. Structural properties of these samples were measured using X-ray diffraction (XRD) and scanning electron microscopy, while magnetic properties were measured using vibrating sample magnetometer (VSM) device. Magnetic and structural characteristics are investigated after preserving Ti-doped BHF samples at room temperature and ambient conditions for 12 years. The samples are characterized using the same previous techniques to find out the possible effect of long period storage on their properties. The results showed that the storage process has little effect on these properties where the granular size increased due to increased oxidation. XRD tests also showed the absence of Ti at low ratios due to increased oxidation of ferrite. VSM results showed increased magnetic properties after storage due to increased iron oxide.


Author(s):  
Shao-Dong Li ◽  
Feng Su ◽  
Cheng-Yong Zhou ◽  
Qi-Long Hu ◽  
Ya-Qi Li ◽  
...  

Two new isostructural complexes, namely, poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)cobalt(II)], [Co(C15H8O7)(C12H8N2)(H2O)] n or [Co(μ3-Hcpota)(phen)(H2O)] n , I, and poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)nickel(II)], [Ni(C15H8O7)(C12H8N2)(H2O)] n or [Ni(μ3-Hcpota)(phen)(H2O)] n , II, have been synthesized by solvothermal reactions. Complexes I and II were fully characterized by IR spectroscopy, elemental analyses, thermogravimetric analyses, and powder and single-crystal X-ray diffraction. They both present two-dimensional structures based on [M 2(μ-COO)2]2+ (M = CoII or NiII) dinuclear metal units with a fes topology and a vertex symbol (4·82). Interestingly, the positions of the two dimeric metal motifs and the two partially deprotonated Hcpota2− ligands reproduce regular flying butterfly arrangements flipped upside down and sharing wings in the ab plane. Magnetic studies indicate antiferromagnetic interactions (J = −5.21 cm−1 for I and −11.53 cm−1 for II) in the dimeric units, with Co...Co and Ni...Ni distances of 4.397 (1) and 4.358 (1) Å, respectively, that are related to double syn–anti carboxylate bridges.


2014 ◽  
Vol 24 (3S1) ◽  
pp. 90-94 ◽  
Author(s):  
Le Tuan Tu ◽  
Luu Van Thiem ◽  
Pham Duc Thang

The magnetic properties in Co-Ni-P nanowires arrays with diameter of 200 nm were investigated. All the samples were prepared by electrodeposition method with pH of 5.5 and at room temperature. During the deposition, a magnetic field in range of 0 - 750 Oe was applied parallel to the wires axis. The crystalline structure and morphology of the samples were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. The hysteresis loops were measured at room temperature using vibrating sample magnetometry (VSM). The mixture of hcp phases of the Co-Ni-P based nanowires has been indicated by the XRD pattern. The obtained results show that with 750 Oe magnetic field applied during deposition we can obtain maximum coercivity value (2180 Oe). The \(M_{r}/M_{s}\) ratio was rapid increased when the magnetic field changed from 0 Oe to 750 Oe.


2011 ◽  
Vol 393-395 ◽  
pp. 947-950
Author(s):  
De Hui Sun ◽  
Ji Lin Zhang ◽  
De Xin Sun

We synthesized Fe3O4 microspheres using a solvothermal method and characterized their morphologies, structures, surface property and magnetism by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) patterns, Fourier transform infrared (FTIR) absorption spectra, and vibrating sample magnetometer (VSM). The results showed that the synthesized Fe3O4 microspheres with a tunable size range of ca. 80–200 nm are composed of many Fe3O4 collective nanoparticles. XRD pattern confirmed that the Fe3O4 microspheres belong to cubic structure. Magnetic investigation reveals that the Fe3O4 microspheres have higher saturation magnetization and negligible coercivity at room temperature.


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