scholarly journals Effect of the Glycine Treatment on Synthesis and Physicochemical Characteristics of Nanosized Ni-Mn Mixed Oxides

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 487
Author(s):  
Ghadah M. Al-Senani ◽  
Omar H. Abd-Elkader ◽  
Nada S. Al-Kadhi ◽  
Nasrallah M. Deraz

Magnetic Ni-Mn mixed oxides based on nanoparticles (NPs) have been developed at 700 °C using a ceramic method and a glycine-assisted auto combustion path. The thermogravimetry–derivative thermogravimetry (TG—DTG), infrared radiation (IR), X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and high resolution transmittance electron micrographs (HRTEM) techniques have been used to characterize as synthesized nanomaterials by evaluating their thermal behavior, structure, distinguishing the components and establishing the morphology. A vibrating sample magnetometer has been used to estimate the magnetic properties of the materials (VSM). The analyses indicate that using a glycine-assisted auto combustion method resulted in formation of cubic spinel NiMn2O4 NPs as a single phase. The ceramic process, from the other side, led to the development of Mn2O3/NiMnO3/NiMn2O4 nanocomposite. The resulting particles being polycrystalline, including average sizes ranging from 10 to 80 nanometers. The prepared NiMn2O4 NPs showed room-temperature ferromagnetism, with an optimal saturation magnetization value of 5.0216 emu/g, according to the magnetic measurement.

2021 ◽  
Author(s):  
Venkatesh Nakiraboina ◽  
Shyam sunder Goud ◽  
Hari Kumar Nama ◽  
D Ravinder ◽  
Veera Somaiah P

Abstract Sm, doped Mg nano ferrites with composition Mg Sm x Fe2 − x O4 (where X = 0.000, 0.025, 0.050, 0.075,0.1) were synthesized by citrate-gel auto-combustion method. The Samples were analyzed through various experimental techniques. The structural confirmation was done with the basic characterization techniques such as XRD (X-ray Powder Diffraction) and Fourier Transform Infrared (FTIR) spectroscopic analysis. To study the optical absorption behavior of the prepared ferrites, UV-visible spectral analysis was carried out. XRD analysis established the formation of single-phase cubic spinel structure of the materials. FTIR spectra has shown two absorption peaks that are characteristic of spinel nano ferrites. The dc electrical resistivities of the Sm doped Mg nano ferrites were studied by using two probe method at the temperature range of 200–500 °C. A plot of log (σT) vs inverse of temperature yields a curve which reveals a semiconducting nature of prepared nano ferrites. The Thermo Electric Power (TEP) studies of prepared samples carried out at high temperature (573K). The values of the Seebeck coefficient and curie temperature of Sm doped Mg nano ferrites were observed. The magnetization measurements were carried out by using Vibrating Sample Magnetometer (VSM).


2012 ◽  
Vol 463-464 ◽  
pp. 1052-1056
Author(s):  
Ai Xiang Zeng ◽  
Jun Yuan

Ni0.6-xZn0.4MgxFe2O4were synthesized by sol-gel auto-combustion method with Zn(NO3.) 2 •6H2O. , Ni(NO3.) )2•6H2O. , Mg(NO3.) )2•6H2O. , Fe(NO3.) )3•9H2O. , COOO2. and NH3•H2O. X-ray diffraction (XRD) analysises show that the sample is single phase and the doping of magnesium makes no difference to nickel-zinc ferrite’s crystal structure; nickel-zinc ferrite has formed after auto-combustion. Scanning electron microscope analysises show that after sintered the sample’s size is more even and the doping of magnesium makes the size smaller and more even too.


2021 ◽  
Author(s):  
Marjaneh Jafari Fesharaki ◽  
Mohammad Reza Jalali ◽  
Leila Karimi ◽  
Ehsan Sadeghi

Abstract Series of CaZrO3:xEu3+ (x=0.01, 0.02, 0.03, 0.04 and 0.05) phosphors have been prepared by low temperature sol-gel auto combustion method. The structure and morphology of the samples were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM). The energy-dispersive X-ray spectroscope (EDX) was employed to analyze the elemental composition of the phosphor. The XRD patterns indicated that the sample was single phase at 350 ◦C with a perovskite structure. The optimum temperature for the single- phase and crystalline phosphors of CaZrO3:xEu3+ was 700 ◦C. Study of photoluminescence (PL) at room temperature showed that the phosphors can be excited by light with a wavelength of 391 nm. The results of emission spectrum showed that the red luminescence of CaZrO3:xEu3+ due to electric dipole transition of 5D0→7F2 was dominant at wavelength of 615 nm and weaker transition at wavelength of 590 nm which was due to magnetic dipole transition of 5D0→7F1. For the thermoluminescence (TL) study the prepared sample irradiated by X-ray lamp, the TL curve was then recorded at fixed heating rate of 2 ◦C/s. The TL glow curve showed well single peak at a temperature of 165 ◦C. The effect of Eu3+ concentration at fixed X-ray exposure time was studied and maximum TL occurred at x=0.02. Also the variation of TL intensity with X-ray time (5 to 15 min) showed linear response with dose. The TL glow peak shows more stability and less fading in prepared phosphor which is suitable for TL dosimetry.


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

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.


2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

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.


2006 ◽  
Vol 20 (29) ◽  
pp. 1879-1882 ◽  
Author(s):  
CHANDRA PRAKASH ◽  
J. K. JUNEJA

In the present paper, we report the effect of Samarium substitution and Niobium doping on the properties of a PZT(52:48). The properties studied are: structural, dielectric and ferroelectric. The samples with chemical formula Pb 0.99 Sm 0.01 Zr 0.52 Ti 0.48 O 3 were prepared by solid-state dry ceramic method. Small amount (0.5 wt%) of Nb 2 O 5 was also added. X-ray diffraction (XRD) analysis showed formation of a single phase with tetragonal structure. Dielectric properties were studied as a function of temperature and frequency. Transition temperature, Tc, was determined from dielectric constant versus temperature plot. The material shows well-defined ferroelectric (PE) hysteresis loop.


2020 ◽  
Vol 31 (10) ◽  
pp. 7871-7879 ◽  
Author(s):  
G. Hosamani ◽  
B. N. Jagadale ◽  
J. Manjanna ◽  
S. M. Shivaprasad ◽  
D. K. Shukla ◽  
...  

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.


2019 ◽  
Vol 33 (19) ◽  
pp. 1950219 ◽  
Author(s):  
Mukhtar Ahmad ◽  
Jawaria Shaheen ◽  
Waseem Abbas Hashmi ◽  
Majid Niaz Akhtar ◽  
Muhammad Asif

In this work, Sr-substituted samples of single-phase spinel monoferrites with chemical formula [Formula: see text] (x = 0.00, 0.33, 0.67, 1.00) were synthesized using sol–gel auto-combustion method. In order to confirm the single-phase formation of these samples, a sample (x = 0.00) was chosen for heat treatment at different temperatures (100, 300, 400, 600 and [Formula: see text]) for 4 h. The heat treated sample was then investigated by X-ray diffraction (XRD) analysis and results showed that a single-phase sample can be successfully synthesized at a temperature of [Formula: see text], which is much lower than that reported in earlier literature for synthesis of same structured samples. All the synthesized samples were then sintered at [Formula: see text] for 4 h to achieve better crystallinity. From XRD patterns, lattice parameters, cell volume and XRD density as a function of Sr-substitution were calculated. Scanning electron microscopy (SEM) results showed that the grain size increased as the temperature was increased. Fourier transform infrared spectroscopy (FTIR) results confirmed the single-phase spinel monoferrites at [Formula: see text]. From M–H loops (x = 0.0, 0.33, 0.67 and 1.00), different magnetic parameters such as saturation magnetization [Formula: see text], remanance [Formula: see text], coercivity [Formula: see text] and magnetic moment [Formula: see text] were calculated. Magnetocrystalline anisotropy constant and Y–K angles of Sr-doped Ba monoferrites were also calculated. In addition, the variation of different dielectric parameters (real permittivity, imaginary permittivity, real permeability, imaginary permeability, ac conductivity and loss tangent) as a function of frequency (1–6 GHz) has been discussed in this work. The results suggest that the synthesized materials have many advantages over previously reported single-phase spinel monoferrites.


Sign in / Sign up

Export Citation Format

Share Document