scholarly journals Engineering of magnetic properties in doped bismuth ferrite materials

2018 ◽  
Vol 218 ◽  
pp. 04027
Author(s):  
Hamdan Akbar Notonegoro ◽  
Bambang Soegijono ◽  
Isom Mudzakir

The engineering of magnetic behaviour of Li/Zn doped BiFeO3 had been done by synthesized a polycrystalline of BiFeO3, Bi0.96Li0.02FeO3, and Bi0.95Zn0.05FeO3. Investigation of crystallite structure and magnetic properties of the sampel had been done by X-ray diffraction and VSM analysis. At room temperature, the lithium and zinc doped bismuth ferrite has conducted a different magnetic behaviour. Within the ferromagnetic region, an increases of magnetic saturation or enlarger magnetic coercivity were identified. Doping lithium resulted in increasing magnetic saturation (Ms) and magnetic remanent (Mr), significantly. Meanwhile, doping zinc resulted in enlarger of magnetic coercivity coincide with the reveal of Bi20FeO40 as the second phase.

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.


2005 ◽  
Vol 879 ◽  
Author(s):  
M. Abid ◽  
C. Terrier ◽  
J-P Ansermet ◽  
K. Hjort

AbstractFollowing the theory, ferromagnetism is predicted in Mn- doped ZnO, Indeed, ferromagnetism above room temperature was recently reported in thin films as well as in bulk samples made of this material. Here, we have prepared Mn doped ZnO by electrodeposition. The samples have been characterized by X-ray diffraction and spectroscopic methods to ensure that the dopants are substitutional. Some samples exhibit weak ferromagnetic properties at room temperature, however to be useful for spintronics this material need additional carriers provided by others means.


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.


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.


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.


2010 ◽  
Vol 8 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Junhao Zhang ◽  
Ling Yang ◽  
Xiaofang Cheng ◽  
Jinmeng Zhang ◽  
Fucai Li

AbstractHierarchical nickel microwires with nanothorns were fabricated through a reduction of nickelous salt with hydrazine in diethanolamine. The product was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). The growth mechanism of the nickel microwires with nanothorns is proposed, based on the evolution of the structures and morphologies, which could be ascribed to the cooperative effect of the complexant of diethanolamine and inherent magnetic interactions. Magnetic properties of the product were measured at room temperature and compared with other shaped counterparts.


2011 ◽  
Vol 110-116 ◽  
pp. 1736-1740 ◽  
Author(s):  
Ju Hua Luo

Sr-ferrite powders were preparated by mechanochemical treatments using SrCO3 and Fe2O3 as raw materials. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM) were employed to evaluated the morphologies, structures and magnetic properties of samples. The results indicated that the starting mixture became amorphous stage after ball-milled for 30h, and single phase SrFe12O19 could be obtained after annealed at 900°C for 2h. And the saturation magnetization was 58.2Am2/kg, and coercivity was 281.2 kA/m at room temperature. In comparison with the traditional firing method , the mechanochemical method benefited achieving the higher coercivity, which indicated that the samples had a better magnetic properties.


2009 ◽  
Vol 152-153 ◽  
pp. 75-78 ◽  
Author(s):  
V.S. Gaviko ◽  
A.G. Popov ◽  
G.V. Ivanova ◽  
N.V. Mushnikov ◽  
Y.V. Belozerov ◽  
...  

We have synthesized a novel intermetallic compound PrFe8Ga3C and studied its structure and magnetic properties. X-ray diffraction analysis revealed that the compound possesses a tetragonal BaCd11-type structure (space group I41/amd). In this structure Ga atoms occupy the same sites as Fe atoms with preferably filling the 4(b) site. Magnetization curves have been measured on the aligned powder samples. Below the Curie temperature TC = 400 K the easy magnetization direction was found to orient within the (100) plane. At 80 K the compound has a spontaneous magnetization of 97 emu/g and anisotropy constant of 4.2107 erg/cm3. At room temperature these values reduce to 78 emu/g and 4.7106 erg/cm3, respectively.


Author(s):  
Mashadi Sunandar

Nanocomposite of α-Fe/C was successfully synthesized by mechanical milling method. Analytical-grade of α-Fe and graphite powders with a purity of greater than 99% were mixed. The mixture was milled for 50 hours at room temperature using High Energy Milling (HEM). The refinement results of X-ray diffraction pattern shows that the α-Fe/C nanocomposite consists of 20 wt% Fe and 80 wt% C. The mechanical milling resulted in α-Fe/C powders with mean particle size ~900 nm. The image reveals the morphology of particle and the particles that exist is aggregates of fine grains. The magnetic properties of the particle α-Fe/C nanocomposite showed low coercivity and high remanent magnetization. The α-Fe/C nanocomposite has certain microwave absorber properties in the frequency range of 9 – 15 GHz, with the maximum reflection loss reaches -10 dB at 12 GHz and the absorption range under −4 dB is from 11.2 to 15.5 GHz with 2 mm thickness. The study concluded that the α-Fe/C nanocomposite shows good candidate materials for microwave absorbing materials applications. 


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