Elaboration of Low Field and Room Temperature Magnetoresistive Sensor of La0.7Sr0.3MnO3 Nanoparticles Synthesized by Sol-Gel Method

2015 ◽  
Vol 771 ◽  
pp. 121-124 ◽  
Author(s):  
Christian Fredy Naa ◽  
Didier Fasquelle ◽  
Manuel Mascot ◽  
Mitra Djamal

Low field and room temperature operation range are two critical requirements for magnetic sensors. In this paper, nanoparticles of La0.7Sr0.3MnO3 (LSMO) were elaborated to fulfill these requirements. La0.7Sr0.3MnO3 nanoparticles were synthesized using sol-gel method. The physical properties of LSMO were examined by X-Ray diffraction and Scanning Electron Microscope. The ferromagnetic nature of LSMO samples was confirmed by magnetization measurements. Nanoparticles were pressed in shape of pellets and sintered at different temperatures of 900°C, 1000°C, 1100°C and 1200°C. Magnetoresistive measurements were taken at room temperature with magnetic field (μH) in range ±110 mT. The experimental results show maximum magnetoresistive ratio and sensitivity of 1.3% and 0.023%/mT respectively for sample sintered at 1000°C. Other sensor characteristics namely hysteresis error, response time and noise measurement were also given.

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 533
Author(s):  
Ewelina Nowak ◽  
Mirosław Szybowicz ◽  
Alicja Stachowiak ◽  
Daria Piechowiak ◽  
Andrzej Miklaszewski ◽  
...  

Zinc oxide (ZnO) is one of the wide-bandgap semiconductors, which may be useful in a plethora of electronic, optical, piezoelectric, and scintillating applications. The following article consists in a structural and luminescence analysis of ZnO microfilms grown on a sapphire substrate with a sol–gel method. The films were annealed at different temperatures. The structures were investigated with the XRD and Raman methods, by which the influence of the substrate on the structure of the film was determined. The luminescence of films was investigated with room-temperature fluorescence, radioluminescence, and thermoluminescence.


2021 ◽  
Vol 37 (1) ◽  
pp. 177-180
Author(s):  
Alimuddin Alimuddin ◽  
Mohd Rafeeq

Synthesis of strontium oxide nanoparticles was carried out by sol –gel method using strontium nitrate and sodium hydroxide at room temperature which is very simple and cost effective. The characterization of strontium oxide nanoparticles was done using X-ray diffraction, scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR). X-ray diffraction pattern indicates that the nanoparticles are crystalline in nature. The crystalline size of strontium oxide nanoparticle was calculated by Debye-Scherrer formula. The crystalline sizes are about 80nm. The morphology of nanoparticles was observed and investigated using SEM. The material at room temperature, calcined at 2000C, 400 0C and 6000C respectively shows pseudo spherical shape, cubic form and finally it becomes cylindrical this shows that there is a agglomeration with increase in temperature. FTIR spectrum of strontium oxide shows the peak at 854.64 cm-1 which is due to Sr -O bond.


2008 ◽  
Vol 25 (7) ◽  
pp. 2638-2641
Author(s):  
Liu Li-Feng ◽  
Kang Jin-Feng ◽  
Wang Yi ◽  
Zhang Xing ◽  
Han Ru-Qi

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.


2021 ◽  
Vol 93 (3) ◽  
pp. 30401
Author(s):  
Jiaxing Wang ◽  
Hai Yu ◽  
Yong Zhang

SnO2 nanoparticle architectures were successfully synthesized using a sol-gel method and developed for acetone gas detection. The morphology and structure of the particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The SnO2 nanoparticle architectures were configured as high-performance sensors to detect acetone and showed a very fast response time (<1 s), a short recovery time (10 s), good repeatability and high selectivity at a relatively low working temperature. Thus, SnO2 nanoparticles should be promising candidates for designing and fabricating acetone gas sensors with good gas sensing performance. The possible gas sensing mechanism is also presented.


Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.


2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.


2018 ◽  
Vol 41 (3-4) ◽  
pp. 53-62 ◽  
Author(s):  
Behnaz Lahijani ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

Abstract In this work, the PbFe12O19 nanoparticles were prepared by the simple and optimized precipitation method with different organic surfactants and capping agents. In the next step, the TiO2 nanoparticles were synthesized using the sol-gel method. At the final step, the PbFe12O19-TiO2 nanocomposites were prepared via the sol-gel method. The effect of the precipitating agent on the morphology and particle size of the products was investigated. The prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The results obtained by the vibrating sample magnetometer show the magnetic properties of the ferrite nanostructures. The photocatalytic effect of the PbFe12O19-TiO2 nanocomposite on the elimination of the azo dyes (acid black, acid violet and acid blue) under ultraviolet light irradiation was evaluated. The results indicate that the prepared nanocomposites have acceptable magnetic and photocatalytic performance.


Author(s):  
T. Pikula ◽  
T. Szumiata ◽  
K. Siedliska ◽  
V. I. Mitsiuk ◽  
R. Panek ◽  
...  

AbstractIn this work, BiFeO3 powders were synthesized by a sol–gel method. The influence of annealing temperature on the structure and magnetic properties of the samples has been discussed. X-ray diffraction studies showed that the purest phase was formed in the temperature range of 400 °C to 550 °C and the samples annealed at a temperature below 550 °C were of nanocrystalline character. Mössbauer spectroscopy and magnetization measurements were used as complementary methods to investigate the magnetic state of the samples. In particular, the appearance of weak ferromagnetic properties, significant growth of magnetization, and spin-glass-like behavior were observed along with the drop of average grain size. Mössbauer spectra were fitted by the model assuming cycloidal modulation of spins arrangement and properties of the spin cycloid were determined and analyzed. Most importantly, it was proved that the spin cycloid does not disappear even in the case of the samples with a particle size well below the cycloid modulation period λ = 62 nm. Furthermore, the cycloid becomes more anharmonic as the grain size decreases. The possible origination of weak ferromagnetism of the nanocrystalline samples has also been discussed.


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