Structural and magnetic properties analysis of trivalent Al3+ ions substituted Ni-Zn-Co nano-spinel ferrites

2021 ◽  
Vol 12 (4) ◽  
pp. 045001
Author(s):  
Nusrat Jahan ◽  
J I Khandaker ◽  
H Das ◽  
M N I Khan

Abstract This study explored the structural, morphological, optical, and magnetic properties of Ni0.4Zn0.35Co0.25Fe2−x Al x O4 (0 ≤ x ≤ 0.12) nano-spinel ferrites. Nanocrystalline cubic structure formation and weight loss percentage were determined by thermogravimetric analysis and differential scanning calorimetry (TGA - DSC). Single-phase cubic spinel structures with Fd3m space group of synthesized samples were confirmed by Rietveld refinement X-ray diffraction (XRD) data. The particle sizes were found to be in the range of 6.7 nm–5.25 nm, and agglomeration occurs inside the ferrite samples. The atomic planes and strong crystallinity were detected through SAED images. The characteristic peaks of the Raman spectra identified the bonding between the cations and anions in the sub-lattices. The optical bandgaps (E g ) were found to be in the range of 2.1 eV–2.52 eV. S-shape hysteresis (M-H) loops identified the superparamagnetic nature of the nano-samples. The studies’ outcomes indicated the applicability for biomedical applications of these nano samples.

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.


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 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.


2018 ◽  
Vol 197 ◽  
pp. 02007
Author(s):  
Erfan Handoko ◽  
Anggoro B S ◽  
Iwan Sugihartono ◽  
Mangasi AM ◽  
Dini Siti Nurwulan ◽  
...  

In In this study to understand the substitutional effect of Co-Zn on structural and magnetic properties of the BaFe12-2xCoxZnxO19 M-type hexagonal ferrites with concentration (x= 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were synthesized by the ceramic method. The results of x-ray diffraction show polycrystalline with single phase. Scanning electron microscopy micrographs shows the hexagonal ferrites that are composed of small particles with large porosity, roughly of spherical shapes. The substitution of Fe3+ ion by Co2+ and Zn2+ has changed magnetic properties of hexagonal ferrites.


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.


2008 ◽  
Vol 23 (11) ◽  
pp. 2880-2885 ◽  
Author(s):  
Herbert Willmann ◽  
Paul H. Mayrhofer ◽  
Lars Hultman ◽  
Christian Mitterer

Microstructure and hardness evolution of arc-evaporated single-phase cubic Al0.56Cr0.44N and Al0.68Cr0.32N coatings have been investigated after thermal treatment in Ar atmosphere. Based on a combination of differential scanning calorimetry and x-ray diffraction studies, we can conclude that Al0.56Cr0.44N undergoes only small structural changes without any decomposition for annealing temperatures Ta ⩽ 900 °C. Consequently, the hardness decreases only marginally from the as-deposited value of 30.0 ± 1.1 GPa to 29.4 ± 0.9 GPa with Ta increasing to 900 °C, respectively. The film with higher Al content (Al0.68Cr0.32N) exhibits formation of hexagonal (h) AlN at Ta ⩾ 700 °C, which occurs preferably at grain boundaries as identified by analytical transmission electron microscopy. Hence, the hardness increases from the as-deposited value of 30.1 ± 1.3 GPa to 31.6 ± 1.4 GPa with Ta = 725 °C. At higher temperatures, where the size and volume fraction of the h-AlN phase increases, the hardness decreases to 27.5 ± 1.0 GPa with Ta = 900 °C.


1991 ◽  
Vol 69 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Jing-Long Du ◽  
Steven J. Rettig ◽  
Robert C. Thompson ◽  
James Trotter

The synthesis of the β and γ forms of M(Ph2PO2)2 where M = Co and Mn are described and the compounds are characterized by infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction, and low-temperature (2–80 K) magnetic susceptibility studies. Single crystal X-ray diffraction studies are reported on the γ forms. Crystals of the γ forms of poly-bis(μ-diphenylphosphinato)cobalt(II) and poly-bis(μ-diphenylphosphinato)manganese(II) are isomorphous, crystallizing with 4 formula units per unit-cell in the monoclinic space group P21/c. Lattice constants are a = 8.080(2), 8.161(1), b = 23.550(6), 23.751(1), c = 11.726(3), 11.6946(6) Ǻ, and β = 92.88(2), 93.026(8)° for the Co and Mn derivatives respectively. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.039 and 0.045 for 4041 and 2878 reflections with I ≥ 3σ(I), respectively. Both crystal structures consist of double phosphinate-bridged chain polymers containing tetrahedrally coordinated metal atoms: Co—O = 1.950(2)–1.963(2) Ǻ, O—Co—O = 104.81(8)–117.77(9)°, Mn—O = 2.016(3)–2.033(3) Ǻ, O—Mn—O = 103.2(1)–114.7(1)°. All four compounds exhibit antiferromagnetic coupling and magnetic susceptibilities have been analyzed according to two Heisenberg models for linear chains of metal ions with S = 3/2 for cobalt and S = 5/2 for manganese. The Weng model (with values for the Wagner and Friedberg model in parentheses) gives –J = 0.25 (0.26) cm−1 and 0.55 (0.60) cm−1 for the β and γ forms, respectively, of Co(Ph2PO2)2, and 0.34 (0.36) cm−1 and 0.17 (0.17) cm−1 for the β and γ forms, respectively, of Mn(Ph2PO2)2. Key words: crystal structure, diphenylphosphinates of cobalt(II) and manganese(II), magnetic properties.


2018 ◽  
Vol 19 (2) ◽  
pp. 47
Author(s):  
Yosef Sarwanto ◽  
Wisnu Ari Adi

Crystallographic structure and magnetic properties of pseudobrookite Fe2-xNixTiO5 system (x = 0, 0.1, 0.2, 0.3, 0.5 and 1) have been performed through solid state reaction. Pseudobrookite Fe2-xNixTiO5 system was synthesized by mixing of Fe2O3, NiO, and TiO2 with stoichiometry composition using wet mill. The mixture was milled for 5 hours and sintered in the electric chamber furnace at 1000 oC in the air at atmosphere pressure for 5 hours. The refinement against of X-ray diffraction data shows that the sampless with composition of (x = 0) and (x = 0.1) have a single phase with Fe2TiO5 structure. However the samples with composition of (x > 0.1) consist of multiple phases, namely Fe2-xNixTiO5, FeTiO3, Fe2NiO4 and NiO. Particle morphologies of the composition x = 0 and x = 0.1 are homogenous and uniform on the sample surface with a polygonal particle shape and particle size varies. At room temperature, the sample with x=0 is paramagnetic and that with x=0.1 is ferromagnetic. Magnetic phase transformation of this study is the caused by the present of Ni substituted Fe in the system. Thus substitution Ni into Fe on the system pseudobrookite Fe2TiO5 only capable of 0.1 at.% without changing the crystal structure of the material. It means that there is an interaction between the magnetic spin Fe3+ on the 3d5 configurations and Ni2+ on the 3d3 configurations through the mechanism of double exchange. Double exchange mechanism is a magnetic type of exchange that appears between the ions Fe3+ and Ni2+ adjacent in different oxidation states.


Author(s):  
Arif Budiman ◽  
Dwi Puryanti ◽  
Sri Mulyadi Dt. Basa ◽  
Muhammad Rizki ◽  
Helfi Syukriani

<p><strong>Abstract:</strong> The synthesis and characterization of the crystal structure and magnetic properties of strontium ferrite magnets (SrO.6Fe<sub>2</sub>O<sub>3</sub>) has been done. Hematite (Fe<sub>2</sub>O<sub>3</sub>) is synthesized from iron sand of Batang Sukam Sijunjung Sumatera Barat through the oxidation process by temperature 700ºC for 3.0 hours. Strontium carbonate (SrCO<sub>3</sub>) was obtained from Merck product with a purity of more than 99%. Synthesis of strontium ferrite magnets are made through a process of solid-solid mixing and sintering at a temperature of 1000ºC for 3.0 hours. The results of characterization of X-ray diffraction indicates that it has formed a single phase strontium ferrite magnets with a hexagonal crystal structure. The result of measurement of the magnetic properties shows that an average magnetic susceptibility of strontium ferrite magnet is 266.7 × 10<sup>-8 </sup>m<sup>3</sup> /kg.</p><p> </p><p><strong>Keywords</strong>: strontium ferrite magnet, iron sand, crystal structure and magnetic susceptibility.</p><p><strong> </strong></p><p><strong>Abstrak:</strong> Telah dilakukan sintesis dan karakterisasi struktur kristal dan sifat magnetik magnet stronsium ferit (SrO.6Fe<sub>2</sub>O<sub>3</sub>). Hematit (Fe<sub>2</sub>O<sub>3</sub>) disintesis daripasir besi Batang Sukam Kabupaten Sijunjung Sumatera Barat melalui proses oksidasi dengan temperatur 700ºC selama 3,0 jam. Stronsium karbonat (SrCO<sub>3</sub>) diperoleh dari produk Merck dengan kemurnian lebih dari 99 %. Sintesis magnet stronsium ferit dibuat melalui proses <em>solid-solid mixing</em> dan disintering pada suhu 1000ºC selama 3,0 jam. Hasil karakterisasi difraksi sinar-X menunjukkan bahwa telah terbentuk <em>single phase</em> magnet stronsium ferit dengan struktur kristal heksagonal. Hasil pengukuran sifat magnet menunjukkan bahwa magnet stronsium ferit memiliki suseptibilitas magnetik rata-rata 266,7 × 10<sup>-8</sup> m<sup>3</sup>/kg.</p><p> </p><p><strong>Kata Kunci:</strong> magnet stronsium ferit, pasir besi, struktur kristal dan suseptibilitas magnetik.</p>


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