Effect of Different Synthesis Methods on Structural, Morphological and Magnetic Properties of La0.7Ba0.25Nd0.05MnO3

2020 ◽  
Vol 860 ◽  
pp. 89-94
Author(s):  
Dicky Rezky Munazat ◽  
Budhy Kurniawan ◽  
Dhawud Sabilur Razaq ◽  
Ikhwan Nur Rahman ◽  
Arief Sudarmaji ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
Double Exchange ◽  
Average Crystallite Size ◽  
Rhombohedral Structure ◽  
Hysteresis Curve ◽  
Synthesis Methods ◽  
Double Exchange Interaction

La0.7Ba0.25Nd0.05MnO3 (LBNMO) compounds were synthesized using two different methods, namely are solid-state reaction (SS) and sol-gel (SG). All samples were heat-treated at 1200 °C for 12 hours. The investigation on structural, morphological, and magnetic properties was carried out by X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM), and Vibrating Samples Magnetometer (VSM) at room temperature. From the Rietveld refinement, both samples have formed a rhombohedral structure with an R-3c (167) space group. The average crystallite size was calculated using the Scherrer formula and Williamson-Hall (W-H) method for comparison. It was shown that the crystallite size of the sample produced by the SG method has larger than the SS method. This result is fairly consistent with the result obtained from SEM analysis, which shows that the average grain for the SG sample is larger than of the grain of the SS samples. From the magnetic hysteresis curve, the magnetization saturation value for the SG was higher and sharper than that of the SS sample. These confirm the occurrence of the double exchange interaction in the samples, which is mainly associated with the reduction of bandwidth and grain size.

Magnetic Properties of the La0.50Ba0.50MnO3 Nanomanganites

2009 ◽  
Vol 152-153 ◽  
pp. 135-138 ◽  
Author(s):  
S.V. Trukhanov ◽  
A.V. Trukhanov ◽  
Christian E. Botez ◽  
H. Szymczak
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Sol Gel ◽  
Exchange Interactions ◽  
Average Crystallite Size ◽  
Anomalous Behavior ◽  
Air Atmosphere ◽  
Crystallite Surface ◽  
Step Heat Treatment ◽  
Lattice Compression

Nanocrystalline La0.50Ba0.50MnO3 manganite was synthesized by an optimized sol-gel method. The initial sample was subjected to step-by-step heat treatment under air atmosphere. The ion stoichiometry, the morphology of crystallites of ceramics, and the magnetic properties were studied. It is established that the average crystallite size increases with increasing annealing temperature. All of the samples studied are characterized by a perovskite-like cubic structure, with the unit cell parameter a increasing continuously with the average crystallite size. The most significant lattice compression occurs in the sample with an average crystallite size of ~ 30 nm. The increase in the average crystallite size causes a nonmonotonic increase in the Curie temperature and in the spontaneous magnetic moment. The anomalous behavior of the magnetic properties of the La0.50Ba0.50MnO3 manganites obtained is explained by the competition between two size effects, namely, the frustration of the indirect exchange interactions Mn3+ – O – Mn4+ on the nanocrystallite surface and the crystal lattice compression due to the crystallite surface tension.

scholarly journals The Structural and Magnetic Properties of Gadolinium Doped CoFe2O4Nanoferrites

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Qing Lin ◽  
Jinpei Lin ◽  
Yun He ◽  
Ruijun Wang ◽  
Jianghui Dong
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Crystallite Size ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Structural And Magnetic Properties

Gadolinium substituted cobalt ferrite CoGdxFe2−xO4(x= 0, 0.04, 0.08) powders have been prepared by a sol-gel autocombustion method. XRD results indicate the production of a single cubic phase of ferrites. The lattice parameter increases and the average crystallite size decreases with the substitution of Gd3+ions. SEM shows that the ferrite powers are nanoparticles. Room temperature Mössbauer spectra of CoGdxFe22−xO4are two normal Zeeman-split sextets, which display ferrimagnetic behavior. The saturation magnetization decreases and the coercivity increases by the Gd3+ions.

Structural and Morphological La0.85-xBaxNa0.15MnO3 (x = 0, 0.05, 0.10 and 0.15) Perovskite Manganite

2020 ◽  
Vol 860 ◽  
pp. 95-100
Author(s):  
Ikhwan Nur Rahman ◽  
Budhy Kurniawan ◽  
Dhawud Sabilur Razaq ◽  
Arief Sudarmaji ◽  
Dicky Rezky Munazat
Keyword(s):  
Structural Parameters ◽  
Sol Gel ◽  
Double Exchange ◽  
Average Crystallite Size ◽  
Lattice Parameter ◽  
Perovskite Manganite ◽  
Sem Images ◽  
Double Exchange Interaction ◽  
Unit Cells ◽  
Ba Substitution

Bulk polycrystalline samples La0.85-xBaxNa0.15MnO3 (x = 0, 0.05, 0.10 and 0.15) manganites were synthesized by the sol-gel route. The effect of Barium (Ba) existence on the structural and morphological was investigated by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The structural parameters were obtained using Rietveld refinement of the XRD pattern. It was revealed the structures of compounds have rhombohedral with R-3c space group without any impurities phase. Furthermore, several changes are found to exist due to Ba substitution such as the lattice parameter, unit cells volume, average crystallite size, average Mn-O bond length (<Mn – O>) and average Mn-O-Mn bond angle (<Mn – O – Mn>). The changes in <Mn – O> and <Mn – O – Mn> due to Ba substitution, affects the double exchange interaction of the samples. SEM images reveal the existence of Ba also affects the morphology of the studied samples, which consisted of polygonal grains with homogeneous chemical composition.

scholarly journals Structural and Magnetic Properties of Co‒Mn Codoped ZnO Nanoparticles Obtained by Microwave Solvothermal Synthesis

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 410 ◽  
Author(s):  
Jacek Wojnarowicz ◽  
Myroslava Omelchenko ◽  
Jacek Szczytko ◽  
Tadeusz Chudoba ◽  
Stanisław Gierlotka ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Doping Level ◽  
Solvothermal Synthesis ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Average Crystallite Size ◽  
Average Particle ◽  
Acetate Tetrahydrate ◽  
Preparation Methods

Zinc oxide nanoparticles codoped with Co2+ and Mn2+ ions (Zn(1−x−y)MnxCoyO NPs) were obtained for the first time by microwave solvothermal synthesis. The nominal content of Co2+ and Mn2+ in Zn(1−x−y)MnxCoyO NPs was x = y = 0, 1, 5, 10 and 15 mol % (the amount of both ions was equal). The precursors were obtained by dissolving zinc acetate dihydrate, manganese (II) acetate tetrahydrate and cobalt (II) acetate tetrahydrate in ethylene glycol. The morphology, phase purity, lattice parameters, dopants content, skeleton density, specific surface area, average particle size, average crystallite size, crystallite size distribution and magnetic properties of NPs were determined. The real content of dopants was up to 25.0% for Mn2+ and 80.5% for Co2+ of the nominal content. The colour of the samples changed from white to dark olive green in line with the increasing doping level. Uniform spherical NPs with wurtzite structure were obtained. The average size of NPs decreased from 29 nm to 21 nm in line with the increase in the dopant content. Brillouin type paramagnetism and an antiferromagnetic interaction between the magnetic ions was found for all samples, except for that with 15 mol % doping level, where a small ferromagnetic contribution was found. A review of the preparation methods of Co2+ and Mn2+ codoped ZnO is presented.

Structural and Magnetic Properties of Nano Composite (Ni1-xSrx Fe12 O19) Prepared by Sol-gel

2021 ◽  
Vol 19 (10) ◽  
pp. 20-28
Author(s):  
Dhifaf Hussain Hassan ◽  
Sabah Jalal Fathi
Keyword(s):  
Magnetic Properties ◽  
Hysteresis Loop ◽  
Quaternary Structure ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Two Phases ◽  
Hematite Fe2o3

The compound was prepared by sol-gel method for spontaneous combustion with certain weight ratios (x=0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9), the samples were calcined at a temperature (900oC) for a period of two hours(2h), then studied its structural and magnetic properties.one of the most prominent results that we obtained from the X-ray diffraction technique (XRD) is that compound has several phases. Where the sample (NiFe2O4) appeared to be polycrystalline and the dominant phase in it is the cubic phase, while the other phase is (Hematite)(Fe2O3) A crystal structure rhomboid (Rhombohedral), in addition to these two phases, the phase with the existing quaternary structure appeared (Sr2Fe2O5) its called (Orthorhombic). The results of the magnetic properties that were obtained through the (VSM) device, and one of the most important of these properties is the magnetic hysteresis loop by analyzing the magnetic hysteresis loop at (x=0.3), where the least area of the hysteresis loop or the least width of the hysteresis loop One of the most important parameters of the magnetic properties is the saturation magnetism (μS) and its value ranges from (19.76-3.86) (emu/gr), the highest value was at (X=0.3) and its value is (19.76emu/gr) and in general its value decreases with increasing concentration of strontium. The residual magnetism (Mr) ranges between (7.45-1.58) (emu/gr), where it reached its highest value at (x=0.3) and its value is (7.45emu/gr), and generally its value decreases with increasing concentration of strontium. In addition to that, there is another parameter which is coercion or Magnetic coercivity (Hc) ranges in value (1751.104-209.26) (Oe), reaching its lowest value at (x=0.3), and then increases with increasing strontium concentration until it reaches its highest value at (x=0.9), where it reached its value is (1751.104Oe). The square rate represented by the symbol (μi) has high values. This means that there is a mutual coupling between the soft and hard magnetic phases, which was the highest value at (x=0.3) and its value is (4.93).

Structure and Morphology Properties of Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 Manganite

2020 ◽  
Vol 860 ◽  
pp. 106-111
Author(s):  
Dhawud Sabilur Razaq ◽  
Budhy Kurniawan ◽  
Ikhwan Nur Rahman ◽  
Dicky Rezky Munazat
Keyword(s):  
Bond Length ◽  
Crystallite Size ◽  
Sintering Temperature ◽  
Bond Angle ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Phase Purity ◽  
X Ray ◽  
Structure And Morphology ◽  
Scanning Electron

Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 manganite have been synthesized using sol-gel method. Afterwards, the samples were sintered at eight different temperature ranging from 650 to 1000 °C. Phase purity, crystal structure and the morphology of the sample have been examined using X-Ray Diffractometer (XRD) and Scanning Electron Microscope. It has been found that different higher sintering temperature greatly affect the phase purity and crystallite size of the sample. Regardless of the sintering temperature, all the samples crystallized in rhombohedral structure with R-3c space group. The crystallite size of the samples is found to increase from 41.59 nm up to 73.42 nm as the sintering temperature increases. Further analysis from XRD result shows that sintering temperature also affect the average Mn-O bond length and Mn-O-Mn bond angle of the sample. The average Mn-O bond length is found to increase while the average Mn-O-Mn bond angle tends to decrease as sintering temperature increases. SEM measurement shows that various grain size ranging from ~100 nm up to ~ 350 nm exists in all the sample regardless the sintering temperature.

AN INVESTIGATION INTO MECHANOCHEMICAL SYNTHESIS OF NANOCRYSTALLINE HEXAFERRITE POWDER

2011 ◽  
Vol 25 (07) ◽  
pp. 987-993
Author(s):  
S. SADEGHI-NIARAKI ◽  
S. A. SEYYED EBRAHIMI ◽  
SH. RAYGAN
Keyword(s):  
Crystallite Size ◽  
Single Phase ◽  
Sol Gel ◽  
Milled Powder ◽  
Particle Morphology ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
High Energy ◽  
Strontium Hexaferrite ◽  
Electron Microscopes

Nanocrystalline strontium hexaferrite powder has been prepared by a new mechanochemical method in which the single phase hexaferrite was obtained via a sol–gel autocombustion process followed by an intermediate high energy milling step and subsequent annealing. The effects of the intermediate milling on the phase evolution, crystallite size and annealing behavior of the final products were investigated using the X-ray diffraction (XRD) technique. The single phase strontium hexaferrite was obtained at an annealing temperature of 800°C, while this temperature was 1,000°C for the powder synthesized without milling. It could be seen that an intermediate milling accelerates the formation of strontium hexaferrite during the calcination process. The results showed that in the milled powder, the average crystallite size of the ferrite was about 40 nm and much smaller than that of the nonmilled powder. Magnetic properties were also measured by a vibrating sample magnetometer (VSM). The particle morphology was then studied by scanning and transmission electron microscopes (SEM and TEM).

Effects of Na-Doping on Structure and Magnetic Properties of LaCoO3

2017 ◽  
Vol 727 ◽  
pp. 403-409
Author(s):  
Yi Hao Shen ◽  
Qing Rong Yao ◽  
Peng Cheng Yang ◽  
Jian Qiu Deng ◽  
Zong Min Wang
Keyword(s):  
Magnetic Properties ◽  
Structure Refinement ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Zero Field ◽  
Ferromagnetic Transition ◽  
Na Doping ◽  
Crystallite Sizes ◽  
Field Cooling

Effect of Na doping on the structural and magnetic properties of La1-xNaxCoO3 (0≤x≤0.4) nanopowder samples synthesized by sol-gel method have been investigated. Rietveld crystal structure refinement of the X-ray diffraction data shows that La1−xNaxCoO3 (x≤0.3) crystallizes in the rhombohedral structure with space group . The lattice parameters decrease and the crystallite sizes increase with the increase of x. For the sample with x=0.4, a secondary hexagonal phase NaCo2O4 was observed. The zero field cooling (ZFC) and field cooling (FC) curve of the samples (x≤0.3) exhibit a paramagnetic-ferromagnetic transition with decreasing temperature.

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