Transformation of Structure, Magnetic Properties and Microwave Absorption Capability in Nd-Doped Strontium Hexaferrite

2020 ◽  
Vol 855 ◽  
pp. 255-260
Author(s):  
Mukhtar Effendi ◽  
Efi Solihah ◽  
Candra Kurniawan ◽  
Wahyu Tri Cahyanto ◽  
Wahyu Widanarto

The synthesize of Nd3+-strontium hexaferrite magnetic material by the solid-state reaction method has been successfully carried out. This study aims to determine the effect of Nd3+ on the structure, magnetic properties, and microwave absorption capability of the material. Preparation of (1-x)SrO:xNd2O3:6Fe2O3 where x = 0, 10, 20, and 30 mol% using basic material in the form of SrCO3 powder, Nd2O3 powder and Fe3O4 from natural iron sand. The characterization includes the X-Ray Diffraction (XRD) examination to determine the crystal structure, the Scanning Electron Microscope (SEM) for exploring the surface morphology, Vibrating Sample Magnetometer (VSM) for the magnetic properties investigation of material, and Vector Network Analyzer (VNA) for microwave absorption capability analysis. The XRD results show that the addition of Nd3+ doping increases the number of SrNdFeO4 phases. The phase has a tetragonal crystal system that has cell parameters a = b = 3.846 Å, and c = 12.594 Å. The magnetic properties of the material showed that the addition of Nd3+ decreased the saturation and remanence magnetization values, whereas the value of the coercivity field increased. Meanwhile, the best microwave absorption occurs in samples with the addition of Nd3+ as much as 0.3 mol, which results in a reflection loss value of -18.9 dB with a frequency bandwidth of 3.9 GHz.

2013 ◽  
Vol 28 (S1) ◽  
pp. S45-S49 ◽  
Author(s):  
A.M. Zhang ◽  
G.T. Zhou ◽  
J. Sun ◽  
T. Xu ◽  
L.L. Guo ◽  
...  

The effect of Dy3+ doping at A-site in hexagonal YMnO3 on the microstructure and magnetic properties was studied. Polycrystalline Y1−xDyxMnO3 samples with x ranging from 0 to 1 were synthesized by the solid-state reaction method. The microstructures of all the samples were studied by X-ray diffraction, which shows that Y1−xDyxMnO3 with a low concentration (x ≤ 0.5) of Dy3+ retains a hexagonal symmetry. The crystal structure refinements of the hexagonal Y1−xDyxMnO3 using the Rietveld method show that the unit-cell parameters of a, c, and unit-cell volume increase with increasing Dy doping, while the MnO5 trigonal bipyramids remain almost unchanged. The remarkable increasing of magnetic moment at a low temperature with increasing the Dy3+ doping concentration is ascribed to the spin order of Dy3+ and the increasing Dy3+–Mn3+ coupling and Mn3+–O–O–Mn3+ interaction.


2013 ◽  
Vol 28 (S1) ◽  
pp. S32-S36 ◽  
Author(s):  
S. Li ◽  
S.F. Jin ◽  
J. Ji ◽  
Z.N. Guo ◽  
W.X. Yuan

In order to complete the research on the Fe–Se binary system, the phase structures with selenium contents from 50 to 60 at.% have been studied. Fe–Se binary samples used in this study were prepared by the high-temperature solid-state reaction method, and the phase structure of each sample was determined by powder X-ray diffraction. The solid solubility of the Fe3Se4 phase was determined to be from 56.1 to 57.6 at.% Se based on the values of unit-cell parameters. Magnetic properties of the samples were also studied.


2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.


2019 ◽  
Vol 13 ◽  
pp. 100393 ◽  
Author(s):  
Martha Rianna ◽  
Timbangen Sembiring ◽  
Marhaposan Situmorang ◽  
Candra Kurniawan ◽  
Anggito P. Tetuko ◽  
...  

2014 ◽  
Vol 979 ◽  
pp. 200-203 ◽  
Author(s):  
Pannipa Chaya ◽  
Tula Jutarosaga ◽  
Wandee Onreabroy

The strontium hexaferrite (SrFe12O19) and Co-substituted strontium hexaferrite (SrCoFe11O19) were prepared by ceramic method. The milled mixture of Fe2O3, SrCO3 and CoO powders were calcined at 1100°C and pellets sintered at 1300°C in air. The crystal structure, morphology and magnetic properties of samples have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM), respectively. The crystal structure of SrFe12O19 was hexaferrite with the crystallite size and the lattice constants a and c of 59.6 nm, 5.8 Å, and 23.0 Å, respectively. Also, the crystal structure of SrCoFe11O19 was hexaferrite with the crystallite size and the lattice constants a and c of 63.7 nm, 5.9 Å and 23.0 Å, respectively. The morphology of obtained samples changed from hexagonal rods to discs shape and grain sizes increased with the increase of doped Co in SrFe12O19. SrFe12O19 with the coercive force (Hc) of 2,133 Oe was classified as hard ferrite magnetic. While, Co-substituted strontium hexaferrite (SrCoFe11O19) was soft ferrite magnetic with coercive force of 64 Oe. Results indicated that magnetic properties of samples such as hard ferrite magnetic and soft ferrite magnetic showed great dependence on the cobalt additive in strontium.


2010 ◽  
Vol 25 (S1) ◽  
pp. S31-S35
Author(s):  
W. H. Zhang ◽  
J. Q. Li ◽  
Y. J. Yu ◽  
F. S. Liu ◽  
W. Q. Ao ◽  
...  

The structural and magnetic properties of the DyCo4−xFexGa compounds with x=0, 0.5, 1, and 1.5 have been investigated by X-ray diffraction and magnetic measurements. Powder X-ray diffraction analysis reveals that each of the DyCo4−xFexGa compounds has a hexagonal CaCu5-type structure (space group P6/mmm). The Fe solubility limit in DyCo4−xFexGa is x<1.5. The higher the value of x, the larger the unit-cell parameters a, c, V, and the 3d-sublattice moment but the smaller the 3d uniaxial anisotropy. Magnetic measurements show that the Curie temperature of DyCo4−xFexGa increases from 498 K for x=0 to 530 K for x=1.5, the compensation temperature Tcomp decreases from 286 K for x=0 to 238 K for x=1.5, and the spin-reorientation transition temperature increases from 403 K for x=0 to 530 K for x=0.5. No spin-reorientation transition was found in the samples with x=1.0 and 1.5. The saturation magnetization of DyCo4−xFexGa measured at 173 K increases but the magnetization measured at 300 K decreases with increasing Fe content x.


2013 ◽  
Vol 03 (04) ◽  
pp. 1350033 ◽  
Author(s):  
Radheshyam Rai ◽  
Shweta Thakur ◽  
M. A. Valente ◽  
Andrei L. Kholkin

The multiferroic ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3 (where RE = Pr , Tb and Dy ) has been synthesized using solid-state reaction technique. Effects of Pr , Tb and Dy substitution on the structure, electrical and ferroelectric properties of ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3 samples have been studied by performing X-ray diffraction, dielectric measurements and magnetic measurements. The crystal structure of the ceramic samples have a monoclinic phase. The vibrating sample magnetometer (VSM) measurement shows a significant change in the magnetic properties of Pr -, Tb - and Dy -doped ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3. It is seen that coercive field (Hc) and remanent magnetization (Mr) increases for Pr but decreases for Dy and Tb .


2015 ◽  
Vol 12 (1) ◽  
pp. 08-14 ◽  
Author(s):  
I Bsoul ◽  
W. I Da'as

In this work, pure and doped with Al (Aluminum) strontium hexaferrite (SrFe12-xAlxO19) were fabricated by solid state reaction method. The Al concentration (x) for the fabricated samples was varied from x=0.0 to x=0.6. Structural and magnetic properties of the fabricated samples were investigated. Analyses of XRD data showed that all samples of high quality, since the measured XRD patterns found to match the standard pattern for single phase of SrFe12O19. The lattice constants a and c were calculated. It was found that the replacement of Fe3+ with Al3+ ions in hexagonal strontium ferrite led to a negligible changes in lattice constant a, whereas the hexagonal lattice constant c found to decrease with increasing the substitution amount of Al. The crystallite size was also determined using the XRD data. It has been found that that Al3+ substitution for Fe3+ does not appreciably disturb the crystallinity of SrFe12-xAlxO19, since the crystallite size for all samples ranged from 83 – 72 nm. The magnetic data showed that doping of strontium with Al leads to a small decrease in saturation magnetization. Also it has been found that the doping of strontium ferrite with Al leads to an increase in the coercivity as a result of increasing of the anisotropy field.


2018 ◽  
Vol 7 (4.30) ◽  
pp. 389
Author(s):  
Nurhabibah Nabilah Ab Mannan ◽  
Sufia Aqilah Razali ◽  
Suhadir Shamsuddin ◽  
Mohamad Zaky Noh ◽  
Zakiah Mohamed

This paper reports influences of cobalt (Co) substituted at Mn-site of Pr­0.75­Na­0.25Mn1-xCo­x­O­3 and Nd0.75Na0.25Mn1-yCoyO3 on structure, electrical transport and magnetic properties. All of the samples were prepared via standard solid state reaction method. X-ray diffraction measurement indicates that all samples were crystallized in an orthorhombic structure (space group Pnma). Resistivity measurement displays the x = 0 sample manifests an insulator behavior while metal-insulator transition was found at 108 K and 84 K for x = 0.02 and 0.05 respectively for Pr­0.75­Na­0.25Mn1-xCo­x­O­3. On the other hand, all of the samples for Nd0.75Na0.25Mn1-yCoyO3 showed insulator behavior down to low temperature and analysis of the resistivity change with respect to temperature, dlnρ/dT-1 versus T reveals a slope changes of resistivity have been recorded. Two obvious peaks were recorded from the analysis for y = 0.02 and 0.05 which can be suggested to the existence of charge order transition at the vicinity. For magnetic properties, x = 0 sample showed a paramagnetic-antiferromagnetic transition and further substitution of Co, x = 0.02 and 0.05, induce the paramagnetic-ferromagnetic transition and antiferromagnetic arrangement respectively. Meanwhile, further substitution of Co, y = 0.02 and 0.05 indicate antiferromagnetic transition with increasing T­N­­­ as Co increased.


2015 ◽  
Vol 05 (04) ◽  
pp. 1520001 ◽  
Author(s):  
Radheshyam Rai ◽  
Poonam Kumari ◽  
M. A. Valente

In this paper, we investigated the influence of rare earth ([Formula: see text] and Gd) doped Ba[Formula: see text]RE[Formula: see text]Ca[Formula: see text]Ti[Formula: see text] Mn[Formula: see text]Nb[Formula: see text]Zr[Formula: see text]O3 (BCTMNZ) ceramics were fabricated by using a conventional solid-state reaction method. The doping effects of La and Gd on the structural and magnetic properties were studied. The structural pattern of the ceramic samples were investigated by X-ray diffraction and the results indicated that both samples shows an orthorhombic structure with pure phase. Strain and crystalline size values for Gd and La doped were 0.31–0.33% and [Formula: see text]–[Formula: see text]m, respectively. The room temperature hysteresis loops were obtained by using a vibrating sample magnetometer. La doped ceramic showed the higher value of magnetization i.e., [Formula: see text]B/f.u. as compared to Gd doped BLTMNZ ceramics.


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