- Article
Authors: Nguyen, Thi Thanh Van; Trương, Thanh Trung; Nguyen, Hoang Nam; Nguyen, Hoang Luong (2014) - Fe60Pt40 nanoparticles have been successfully prepared by sonochemistry method from the solution of Fe(C2H3O2)2 and H2PtCl6. The as-prepared sample then has been annealed at temperatures from 450oC to 650oC. Annealed samples have ordered L1o phase with face-centered tetragonal (fct) structure and show hard magnetic properties. The nanoparticles annealed at 550oC show highest coervicity of 4.36 kOe measured at room temperature. The annealed-temperature dependence of the coercivity is consistent with the appearance of the order phase L1o in the samples.
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- Thesis
Authors: Phạm, Quang Anh; Advisor: Nguyen, Hoang Luong; Luu, Manh Quynh (2022) - The main objectives of this thesis consist of: Synthesizing Fe50Pd50 nanoparticles with and without presence of CTAB. Comparing appearance, structural properties and magnetic properties of FePd nanoparticles synthesized with and without CTAB. Attempting to produce single phase L10 FePd nanoparticles
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- Article
Authors: Truong, Thanh Trung; Nguyen, Thi Thanh Van; Nguyen, Hoang Nam; Nguyen, Hoang Luong (2015) - Magnetic properties of magnetic nanoparticles FePt prepared by sonochemistry were investigated. Upon annealing at temperature from 450ºC to 650ºC samples have ordered L10 structure and show hard magnetic properties. Influence of heat treatment conditions (annealing temperature, cooling rate) on the magnetic properties of the annealed samples has been studied.
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- Article
Authors: Nguyen, Hoang Luong; Nguyen, Hoang Hai; Nguyen, Dang Phu (2009) - Fe-Pt materials have been widely prepared by vacuum evaporation technique. Recently, chemical and physicochemical methods have been successfully used to make Fe-Pt nanoparticles, thin films. This paper reported another physicochemical method, namely sonoelectrodeposition, to produce Fe-Pt nanoparticles. In the sonoelectrodeposition, the electrodeposition process was assisted with a sonicator. The Ti horn of the sonicator played a role as the cathode on which Fe-Pt nanoparticles were deposited. After a certain time of deposition, a sonic pulse was applied to remove the particles from the Ti cathode. The composition of Fe-Pt particles can be controlled by changing the concentration of F...
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- Article
Authors: Nguyen, Thai Ha; Nguyen, Hoang Hai; Nguyen, Hoang Luong (2008) - Fe3O4 nanoparticles have been prepared by the microemulsion technique with water as
the aqueous phase, n-hexane as the oil phase and Span 80 as the surfactant. The reaction occurred under air, N2 or high temperature and high pressure atmosphere. Particle size can be controlled by the oncentration of the reactants dissolved in water, the ratio of water/surfactant and the
atmospheric conditions. The particle size is of 6 - 20 nm. They are superparamagnetic with the saturation magnetization of 50 emu/g. Functionalization of the particle surface has been carried out by using a single layer of oleic acid for hydrophilic surface and double layer of oleic acid and
sodium dodecyl sulfate f...
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- Article
Authors: Hoang, Ngoc Lam Huong; Nguyen, Minh Hieu; Nguyen, Thi Tien; Nguyen, Tran Thuat; Nguyen, Hoang Luong (2017) - Nb-doped Ti thin films were fabricated by co-sputtering of TiO2 doped 6 at% by Nb2O5 and Nb targets. The anatase polycrystalline thin films were obtained by post-annealing at 350oC in vacuum atmosphere. The electrical properties of the films were determined by the Hall method using standard clove-leaf geometry. When the Nb concentration increased, the number of electron increased from 4×1018 cm-3 to 2.4×1020 cm-3, while the resistivity fell down from 10 to 3.5×10-3 Ωcm. It means that this co-sputtering process can be considered as a method to improve conducting properties of Nb:Ti thin films. With low resistivity and high optical transmittance (higher than 80% in the visible range), t...
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- Article
Authors: Nguyen, Hoang Nam; Nguyen, Hoang Luong (2014) - Magnetic memory effect was newly observed in spin-glass magnetic La0.6Sr0.4MnO3 perovskite nanoparticles prepared by sol-gel method. The applied magnetic field and the temperature were changed in defined protocols during the magnetic relaxation process and the magnetic memory effect occured at temperature below blocking temperature which is around room temperature. This magnetic memory effect can be explained by the energy distribution in comparison with strong interaction systems.
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- Article
Authors: Truong, Thanh Trung; Do, Thi Nhung; Nguyen, Thi Thanh Van; Nguyen, Hoang Nam; Nguyen, Hoang Luong (2016) - CoxPt100- x nanoparticles (x=50, 59, and 73) were prepared by the chemical reduction of Cobalt (II)
chloride and Chloroplatinic acid, then ultrasonicated for 2 h. After annealing at various temperatures
from 450 C to 700 C for 1 h, structure change was observed and samples show hard magnetic prop-erties which depend strongly on chemical composition and annealing temperature. The highest coer-civity value of 1.15 kOe was obtained at room temperature for sample with x =50 annealed at 500 C. Chemical reduction combined with ultrasound is a useful method to prepare CoPt nanoparticles
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- Article
Authors: Tran, Quoc Tuan; Pham, Van Hao; Luu, Manh Quynh; Nguyen, Hoang Luong; Nguyen, Hoang Hai (2015) - Silver nanoparticles colloid has been prepared by heat-combined electrochemical method, which uses simple and low-cost equipment of easy installation and operation, is easily deployed in industrial scale. A silver plate was used as the cathode instead of silver salts to avoid unexpected ions from the salts. The cathode was made from a stainless steel plate. The chemical used as the electrolyte solution is TriSodium Citrate (TSC). Silver nanoparticles made by the above method are spherical, small-sized, its size distribution ranges from 3-12nm, stably dispersing in a non-toxic solution.
Bactericidal capacity of silver nanoparticles are tested on 4 types of common bacteria and fungi....
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- Article
Authors: Nguyen, Hoang Luong; Nguyen, Thi Mai Phuong; Phung, Thu Hien; Hoang, Nam Nhat; Luc, Huy Hoang (2008) - Study of the effect of Nd substitution for La on magnetocaloric effect (MCE) of polycrystalline perovskites (Lai^NdOojSrojMnOj (x = 0.0, 0.2 , 0.4, 0.6, 0.8, 1.0 ) is presented. Large MCE is observed in all samples. The presence of Nd affects to both maximum magnetic entropy change, lASmlmax, and Curie temperature, Tc- |AS„,|nax slightly reduces with low content and increases with high content of Nd and gets maximum value of 4.83 J/kg.K for X = 0.8. Tc of the samples determined from the thermo magnetic curves some what increases from 346 K for X = 0.0 to 350 K for X = 0.2, then decreases to 235 K for X = 1.0. The sam ple w ith X = 0.4 exhibiting the largest value of 74 J/kg for the re...
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- Thesis
Authors: La, Thi Ngoc Mai; Advisor: Bui, Nguyen Quoc Trinh; Nguyen, Hoang Luong (2021) - In this thesis, CuO thin films doped with transition metal ions Ni were fabricated by the solution-processed method. Using the spin-coating process, thin films with various Ni doping ratios were coated on glass and ITO substrates. The structural, morphological, optoelectrical and magnetic characteristics of the thin films are all studied. The achievement results pointed out that the Ni-doped CuO films obtained can be considered for a channel of thin film transistors or the applications in spintronic devices and noise suppressors.
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- Thesis
Authors: Nguyễn, Thị Thanh Hoài; Advisor: Nguyen, Hoang Luong; Hoàng, Thị My Nhung (2020) - Overthe past few decades, silver nanoparticles (AgNPs) attractraptattention in wound treatmentdue to various featured natures such as the history of using silver, simple and effective synthesized methods, and above all the outstanding antimicrobial activity. These makeAgNPs become one of the most widely used agents for preventing infection. On the other hand,mesenchymal stem cells (MSCs)and products derived from MSCs, which appear as advanced therapies, have recently been studied and appliedinthe field of medicine. In termsof wound healing, many studies suggestthat paracrine signaling of MSCsrather than tissue differentiationand engraftment is a pivotalelement for promotingwound heali...
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- Article
Authors: Nguyen, Hoang Luong; Nguyen, Ngoc Long; Le, Van Vu; Nguyen, Hoang Hai; Luu, Manh Quynh (2009) - Sphere-like gold nanoparticles have been prepared by chemical reduction method and by using X-ray irradiation, while rod-like gold nanoparticles were synthesized according to the seed-mediated growth method and by sonoelectrochemistry. Sphere-like gold nanoparticles have diameter of 20 - 60 nm, while rod-like gold nanoparticles have aspect ratio from 2 to 4. In UV-vis spectra the absorption bands related to surface piasmon resonance were observed. CoPt nanoparticlcs with the size of 5 - 20 nm have been prepared by electrodeposition, while FePt Iianoparticles with the size of 5 - 10 nm were synthesized by sonoclectrodeposition. After annealing, these magnetic nanoparticles showed a hig...
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- Article
Authors: Chu, Tien Dung; Luu, Manh Quynh; Nguyen, Phuong Linh; Nguyen, Hoang Luong; Nguyen, Hoang Nam (2016) - ZnS:Mn- Fe3O4 bifunctional nanoparticles were synthesized by inverse microemulsion method for
biomedicine applications. The bifunctional nanoparticles were combined from prepared ZnS:Mn and
Fe3O4 nanoparticles in a SiO2 cover matrix. Results show that bifunctional nanoparticles, apart from
exhibiting magnetism, have photoluminescence properties, which support the applications targeting
biomedicine fluorescent diagnostics as well as magnetic cell sorting or drug delivery.
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- Article
Authors: Nguyen, Thi Thanh Van; Truong, Thanh Trung; Nguyen, Hoang Nam; Nguyen, Hoang Luong (2012) - Hard magnetic properties of magnetic nanoparticles FePd were investigated in dependence of temperature. Magnetic nanoparticles FePd were prepared from palladium acetate and iron acetate by sonoelectrochemistry, an useful technique to make metallic nanoparticles using ultrasound. Upon the annealing at 450°C to 650°C samples have ordered L10 structure and show hard magnetic properties with high coercivity up to 2.1 kOe at room temperature and increases to 2.43 kOe with decreasing temperature down to 2 K.
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- Article
Authors: Luu, Manh Quynh; Nguyen, Thi Tien; Nguyen, Ba Loc; Vu, Quang Tho; Nguyen, Thi Lan; Pham, Van Thanh; Nguyen, Minh Hieu; Hoang, Ngoc Lam Huong; Nguyen, Hoang Luong (2017) - The proportional relationship between the infrared (IR) transmittance of a transparent material and its IR-induced heat transfer can be explained via a simple model. The agreement between theory and the experimental work was examined by measuring the temperature rising inside a heat-insulated box with glass windows under IR irradiation, where the material of the glass windows was modified from corning glass (CG) to 9 at% Nb-doped TiO2 (TNO) fabricated by sputtering deposition. The fabricated TNO thin film was mostly transparent in visible region and had low transparency in IR region, which produced the self-cooling effect inside the insulated box. In comparison to the window glass mad...
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