scholarly journals Influence of the B-site cation nature on crystal structure and magnetic properties of Ca2BMoO6 (B = Cr, La, Sm) double perovskite

2014 ◽  
Vol 22 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Ioana A. Gorodea
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Double Perovskite ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
Auto Combustion ◽  
The Fourier Transform ◽  
First Time

Abstract Double perovskite-type oxide Ca2BMoO6 materials, where B = Cr, La and Sm, were prepared by the sol-gel auto-combustion method for the first time. The role of different B-site cations on their synthesis, structures, and magnetic properties was investigated. The synthesis progress was followed by the Fourier transform infrared spectroscopy and the samples’ structure was investigated by X-ray diffraction. The increase of the ionic radii B leads to the decrease of the t-value which reflects the structural distortion from the ideal cubic perovskite. Magnetization measurements were made with a SQUID magnetometer. All compounds are ferimagnetic and magnetic properties are indirectly influenced by the distortion degree of the lattice and disorder on the B/B’ positions

Influence of the B-site cation nature on dielectric properties of Ca2XBiO6 (X = Dy, Fe, Al) double perovskite

2013 ◽  
Vol 67 (10) ◽  
Author(s):  
Simona Feraru ◽  
Petrisor Samoila ◽  
Valentin Nica ◽  
Alexandra Iordan ◽  
Mircea Palamaru
Keyword(s):  
Dielectric Properties ◽  
Sol Gel ◽  
Double Perovskite ◽  
Combustion Method ◽  
Dielectric Behavior ◽  
X Ray Diffraction ◽  
Auto Combustion ◽  
Semiconductor Behavior ◽  
The Fourier Transform ◽  
First Time

AbstractFor the synthesis of Ca2XBiO6 (X = Dy, Fe, Al) metal oxides with ordered double-perovskite structure, the sol-gel auto-combustion method has been used for the first time. The synthesis progress was followed by the Fourier transform infrared spectroscopy and the samples structure was investigated by X-ray diffraction. The samples morphology was studied by means of scanning electron microscopy. The influence of the nature of the trivalent B-site cation on the dielectric properties was evaluated by resistivity measurements in vacuum at frequencies between 102–105 Hz. The best dielectric behavior was obtained for Ca2AlBiO6 and Ca2DyBiO6, while the best semiconductor behavior was found for Ca2FeBiO6.

Impact of Cations Nature of Double Perovskite Ca2BWO6 on Structure and Magnetic Properties

2017 ◽  
Vol 68 (3) ◽  
pp. 504-506
Author(s):  
Ioana A. Gorodea ◽  
Nicoleta Cornei ◽  
Ion Sandu
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Double Perovskite ◽  
Combustion Method ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Perovskite Type Oxide ◽  
The Fourier Transform ◽  
Perovskite Type

The aim of this work is to study the perovskite-type oxide Ca2BWO6 materials, where B = Cr, La and Sm, obtained by the sol�gel citrate-combustion method. The nature of the B-site cations influences the structure and properties of these compound. The synthesis progress was evaluated using X-ray diffraction and the structure of the samples was characterized by the Fourier transform infrared spectroscopy. In our case, the tolerance factor decrease with increasing of the ionic radius B leads to the structural distortion different from the cubic one. The magnetic properties were evaluated by a SQUID magnetometer and they are discussed in relationship with their compositions. From experimental data, it was noticed that all compound are ferromagnetic.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

Study of the magnetic and structural properties of Al–Cr codoped Y-type hexaferrite prepared via sol–gel auto-combustion method

2015 ◽  
Vol 29 (14) ◽  
pp. 1550090 ◽  
Author(s):  
O. Mirzaee ◽  
R. Mohamady ◽  
A. Ghasemi ◽  
Y. Alizad Farzin
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Combustion Method ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Shape ◽  
Auto Combustion ◽  
Xrd Patterns ◽  
Cr Doping

Nanostructure of Y-type hexaferrite with composition of Sr 2 Ni 2 Al x/2 Cr x/2 Fe 12-x O 22 (where x are 0, 0.6, 1.2, 1.8, 2.4 and 3) were prepared by sol–gel auto-combustion method. The influence of Al and Cr doping on the structural and magnetic properties has been investigated. The X-ray diffraction (XRD) patterns confirm phase formation of Y-type hexaferrite. The microstructure and morphology of prepared samples were studied by high resolution field emission scanning electron microscope (FESEM) which shows the hexagonal shape for all of the samples. Magnetic properties were characterized using vibrating sample magnetometer (VSM). The magnetic results revealed that by increasing the Al and Cr to the structure, the coercivity was also increased from 840 Oe to 1160 Oe. Moreover it has been shown that with addition of dopants, saturation magnetization (Ms) and remnant magnetization (Mr) were decreased from 39.61 emu/g to 30.11 emu/g and from 17.51 emu/g to 14.62 emu/g, respectively, due to the entrance of nonmagnetic ions into Fe 3+ sites.

Magnetic Properties and Unusual Morphologies of Barium Ferrites Prepared by Electrospinning and Sol-Gel Auto-Combustion Method

2015 ◽  
Vol 815 ◽  
pp. 141-146 ◽  
Author(s):  
Gui Fang Liu ◽  
Run Hua Fan ◽  
Ke Lan Yan ◽  
Xu Ai Wang ◽  
Kai Sun ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Barium Ferrite ◽  
Raw Materials ◽  
Sol Gel ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion ◽  
Electrospinning Method ◽  
Barium Ferrites

Barium ferrite fibers and barium ferrite powders were successfully prepared respectively via Electrospinning method and sol-gel auto-combustion method by using Fe (NO3)3·9H2O, Ba (NO3)2 as one of the main raw materials. X-ray diffraction (XRD) and field emission scanning electron microscope (FSEM) were used to study the phase composition and microstructure of barium ferrite. The results showed that barium ferrite fibers consist of a mixture of barium ferrite particles, the diameter of fibers is about 200 nm; barium ferrite powders prepared by sol-gel auto-combustion method were flake barium ferrite compositing of rod-like grains of less than 100 nm in size stacking disorderly. Magnetic properties were investigated by vibrating sample magnetometer (VSM), the results showed that the values of Mr, Ms, and Hc of barium ferrite fibers and powders are quite different due to their different morphologies.

Doping Effect on Crystal Structure and Magnetic Properties of Highly Al-Substituted Strontium Hexaferrite Nanoparticles

2012 ◽  
Vol 229-231 ◽  
pp. 210-214
Author(s):  
Elham Khorashadizade ◽  
Hadi Arabi ◽  
Abbas Yousefi
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Sol Gel ◽  
Combustion Method ◽  
Peak Position ◽  
Strontium Hexaferrite ◽  
Ionic Radii ◽  
Al Content ◽  
Auto Combustion ◽  
Substitution Ratio

M-type strontium hexaferrites with substitution of Fe3+by Al3+, according to the formula SrAlxFe12-xO19(x=0, 1, 2, 3, 4, 6, 8, 10), are prepared by the sol-gel auto-combustion method. Influences of the substituted amount of Al3+on structure and magnetic properties of SrAlxFe12-xO19compounds have systematically been investigated by XRD, TEM and VSM. X-ray diffraction shows that the samples are single M-type hexagonal ferrites. Because of the resemblance of Al3+ionic radii with Fe3+the two ions are easily replaced at any substitution ratio without changing the crystal structure. The materials show structural and morphology changes upon replacement of iron by aluminum. A shift in peak position to larger angles shown by XRD is observable with increasing aluminum doping. The values of Ms, Mr and Hc decrease with the addition of Al content but there is an exception for x=3 when Hc=8.9 KOe.

scholarly journals Optimization of synthesis conditions and the study of magnetic and dielectric properties for MgFe2O4 ferrite

2013 ◽  
Vol 11 (8) ◽  
pp. 1330-1342 ◽  
Author(s):  
Alin Druc ◽  
Anca Dumitrescu ◽  
Adrian Borhan ◽  
Valentin Nica ◽  
Alexandra Iordan ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Spinel Structure ◽  
Sol Gel ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Auto Combustion ◽  
Magnetic And Dielectric Properties ◽  
First Time

AbstractNano-sized magnesium ferrites were synthesized by the sol-gel auto-combustion method using a variety of chelating/combustion agents: tartaric acid, citric acid, cellulose, glycine, urea and hexamethylenetetramine. The original purpose of this work was the synthesis of nano-sized magnesium ferrite by using, for the first time, cellulose and hexamethylenetetramine as chelating/combustion agents. Synthesized samples were subjected to different heat treatments at 773 K, 973 K and, respectively 1173 K in air. The disappearance of the organic phase and nitrate phase with the spinel structure formation was monitored by infrared absorption spectroscopy. Spinel structure, crystallite size and cation distribution were evaluated by X-ray diffraction data. The morphology of as-prepared powders was studied using scanning electron microscopy. The magnetic and dielectric properties were studied for the obtained samples.

scholarly journals Sol–gel auto combustion synthesis, characterization, and application of Tb2FeMnO6 nanostructures as an effective photocatalyst for the discoloration of organic dye contaminants in wastewater

RSC Advances ◽  
2021 ◽  
Vol 11 (43) ◽  
pp. 26844-26854
Author(s):  
Mina Dara ◽  
Mohammad Hassanpour ◽  
Omid Amiri ◽  
Mahin Baladi ◽  
Masoud Salavati-Niasari
Keyword(s):  
Combustion Synthesis ◽  
Sol Gel ◽  
Double Perovskite ◽  
Combustion Method ◽  
Organic Dye ◽  
Photocatalytic Properties ◽  
Auto Combustion ◽  
First Time

In this study, new double perovskite Tb2FeMnO6 nanoparticles were successfully synthesized by a sol–gel auto combustion method for the first time. The photocatalytic properties of the nanoparticles were also evaluated for the first time.

scholarly journals Effect of Heat Treatment on Structural and Magnetic Properties of Li-Ni Ferrite Prepared via Sol-Gel Auto-Combustion Method

2021 ◽  
Author(s):  
Jiali Song ◽  
Zhi Wang ◽  
Yu Gao
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Combustion Method ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion ◽  
Ft Ir

Abstract Nanocrystalline Li 0.35 Ni 0.3 Fe 2.35 O 4 ferrites were prepared at different annealing temperature by sol-gel auto-combustion method. The effects of the annealing temperature on the structure and magnetic properties of the synthesized Li-Ni ferrites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR) and Squid-VSM. Rietveld refinement of the X-ray diffraction data confirmed the occurrence of phase transition from α-spinel to β-spinel, from which the ideal cation occupation and lattice parameter can be obtained. The grain size increased significantly with annealing temperature. The variation of saturation magnetization can be well explained in terms of the occupation of ions in tetrahedron and octahedron. The coercivity initially increased and later decreased significantly from 115 to 37 Oe with the increase of annealed temperature which could be attributed the fact that the 600℃-annealed grain size is close to transition size from single to multidomain region.

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