Mossbauer studies of Zn-substituted BiFeO3 multiferroic

2021 ◽  
pp. 2150309
Author(s):  
Guoqing Liu ◽  
Min Liu ◽  
Jin Liu ◽  
Shuang Deng ◽  
Anguo Peng
Keyword(s):  
Magnetic Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Paramagnetic Doublet ◽  
Auto Combustion ◽  
Ion Substitution ◽  
Diffraction Peaks ◽  
Synthesized Materials

This work presents an elaborate study of the effect in the structural and magnetic of BiFe[Formula: see text]Zn[Formula: see text]O3 ([Formula: see text], 0.05, 0.10, 0.15, 0.20, 0.25) multiferroic materials, synthesized via a sol-gel auto-combustion method. The synthesized materials are found to have structural distortion in the rhombohedral R3c structure as observed by X-ray diffraction (XRD). Other diffraction peaks were attributed to the second phase Bi[Formula: see text]FeO[Formula: see text]. The Mossbauer spectra (MS) of BiFe[Formula: see text]Zn[Formula: see text]O3 ([Formula: see text], 0.05, 0.10, 0.15) are fitted with a sextet and a doublet, and the presence of doublet also indicates the Bi[Formula: see text]FeO[Formula: see text] phase. The results from XRD and MS both show that Zn-substituted BiFeO3 suffers adverse effects on the formation of pure BiFeO3. BiFe[Formula: see text]Zn[Formula: see text]O3 ([Formula: see text], 0.25) are fitted with only one paramagnetic doublet. The absence of sextet means that there is a magnetic destruction of samples on account of a thorough phase transition from a magnetic phase to a non-magnetic phase and/or successful ion substitution (iron ions were replaced with zinc ions).

scholarly journals Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Auto Combustion

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.

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.

scholarly journals Structural and Magnetic Property of Cr3+ Substituted Cobalt Ferrite Nanomaterials Prepared by the Sol-Gel Method

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2095 ◽  
Author(s):  
Jinpei Lin ◽  
Jiaqi Zhang ◽  
Hao Sun ◽  
Qing Lin ◽  
Zeping Guo ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Sol Gel ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Cobalt Chromium ◽  
X Ray Diffraction ◽  
Chromium Doping ◽  
Auto Combustion ◽  
Cr Concentration

Cobalt-chromium ferrite, CoCrxFe2−xO4 (x = 0–1.2), has been synthesized by the sol-gel auto-combustion method. X-ray diffraction (XRD) indicates that samples calcined at 800 °C for 3 h were a single-cubic phase. The lattice parameter decreased with increasing Cr concentration. Scanning electron microscopy (SEM) confirmed that the sample powders were nanoparticles. It was confirmed from the room temperature Mössbauer spectra that transition from the ferrimagnetic state to the superparamagnetic state occurred with the doping of chromium. Both the saturation magnetization and the coercivity decreased with the chromium doping. With a higher annealing temperature, the saturation magnetization increased and the coercivity increased initially and then decreased for CoCr0.2Fe1.8O4.

Effect of Annealing Temperature of CoCr2O4 on Structural and Vibrational Properties

2019 ◽  
Vol 11 (11) ◽  
pp. 1079-1081 ◽  
Author(s):  
Prachi Joshi ◽  
Pallavi Saxena ◽  
M. D. Varshney ◽  
V. N. Rai ◽  
A. Mishra
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Auto Combustion ◽  
Different Temperatures ◽  
Disorder Effect ◽  
High Calcination Temperature

CoCr2O4 nanoparticles were prepared by low-temperature sol–gel auto combustion method. In this paper, we have investigated the structural behavior of CoCr2O4 nanoparticles annealed at two different temperatures (600 °C and 800 °C). From the X-ray diffraction (XRD) pattern of CoCr2O4, we have found that there is no change in crystalline structure and it was indexed in the cubic spinel structure with space group Fd3m. It was observed that average crystallite size increases with calcination temperature. High calcination temperature reduced the noise level and enhanced the accuracy of calculated parameters. For both the samples of CoCr2O4, we observed Raman scattering modes at around 471, 516, 539, 561, 590, 626 and 688 cm–1. The additional modes in vibrational spectra appear due to the disorder effect.

scholarly journals Structural, Optical, and Catalytic Properties of MgCr2O4 Spinel-Type Nanostructures Synthesized by Sol–Gel Auto-Combustion Method

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1476
Author(s):  
Vasyl Mykhailovych ◽  
Andrii Kanak ◽  
Ştefana Cojocaru ◽  
Elena-Daniela Chitoiu-Arsene ◽  
Mircea Nicolae Palamaru ◽  
...  
Keyword(s):  
Tartaric Acid ◽  
Catalytic Properties ◽  
Spinel Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
Temperature Treatment ◽  
X Ray Diffraction ◽  
Spinel Type ◽  
X Ray ◽  
Auto Combustion

Spinel chromite nanoparticles are prospective candidates for a variety of applications from catalysis to depollution. In this work, we used a sol–gel auto-combustion method to synthesize spinel-type MgCr2O4 nanoparticles by using fructose (FS), tartaric acid (TA), and hexamethylenetetramine (HMTA) as chelating/fuel agents. The optimal temperature treatment for the formation of impurity-free MgCr2O4 nanostructures was found to range from 500 to 750 °C. Fourier transform infrared (FTIR) spectroscopy was used to determine the lattice vibrations of the corresponding chemical bonds from octahedral and tetrahedral positions, and the optical band gap was calculated from UV–VIS spectrophotometry. The stabilization of the spinel phase was proved by X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analysis. From field-emission scanning electron microscopy (FE-SEM), we found that the size of the constituent particles ranged from 10 to 40 nm. The catalytic activity of the as-prepared MgCr2O4 nanocrystals synthesized by using tartaric acid as a chelating/fuel agent was tested on the decomposition of hydrogen peroxide. In particular, we found that the nature of the chelating/fuel agent as well as the energy released during the auto-combustion played an important role on the structural, optical, and catalytic properties of MgCr2O4 nanoparticles obtained by this synthetic route.

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.

Structural and Electrical Conductivity Studies in Nickel Ferrite Nano-Particles

2013 ◽  
Vol 209 ◽  
pp. 177-181 ◽  
Author(s):  
Ram S. Barkule ◽  
D.V. Kurmude ◽  
A.V. Raut ◽  
N.N. Waghule ◽  
K.M. Jadhav ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Nickel Ferrite ◽  
Sol Gel ◽  
Chelating Agent ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

Abstract: The magnetic nano-particles of nickel ferrite were synthesized successfully by sol-gel auto-combustion method using high purity metal nitrates and citric acid as chelating agent. The as prepared powder of nickel ferrite was sintered at 5500C for 5 hr to obtain good crystalline phase and was used for further study. The X-ray diffraction technique was employed to confirm the single phase formation of nickel ferrite nano-particles. The X-ray diffraction pattern shows the Bragg’s peak which belongs to cubic spinel structure. The values of lattice constant, X-ray density, oxygen parameter and radii of tetrahedral and octahedral sites were calculated from XRD data. The average crystallite size was estimated using Scherrer’s formula and found to be 6 nm. The temperature dependence of the electrical conductivity plot shows the kink, which can be attributed to ferromagnetic-paramagnetic transition. The activation energy obtained from resistivity plots in paramagnetic region is found to be more than that in ferrimagnetic region. The conduction mechanism in these nickel ferrite nano-particles has been discussed on the basis of hopping of electrons.

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

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