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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

M4SF-20LL010302042: Process Model for Radionuclide Incorporation into Corrosion Products

This progress report (Level 4 Milestone Number M4SF-20LL010302042) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Activity Number SF-20LL010302041. The research is focused on actinide and radionuclide sequestration in steel corrosion products. Fuel matrix degradation models suggest that the near field is likely to be reducing at the time of canister breaching, steel corrosion, and radionuclide release, but more oxidizing conditions may prevail in the far field. The incorporation of radionuclides into corrosion phases may limit the rate of radionuclide release by sequestering a portion of the radionuclide source term. For these reasons there is a need to evaluate the incorporation of Pu and other radionuclides into various Fe-oxide phases, and to understand the behavior of coprecipitated phases during mineral recrystallization processes and during re-oxidation events. Radionuclide coprecipitation with Fe minerals may impact long-term repository performance and is an ongoing research focus at Lawrence Livermore National Laboratory.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Steel Corrosion Impacts on Radionuclide Immobilization

This progress report (Level 4 Milestone Number M4SF-21LL010302052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Activity Number SF-21LL01030205. The research is focused on actinide and radionuclide sequestration in steel corrosion products. Fuel matrix degradation models suggest that the near field is likely to be reducing at the time of canister breaching, steel corrosion, and radionuclide release, but more oxidizing conditions may prevail in the far field. The incorporation of radionuclides into corrosion phases may limit the rate of radionuclide release by sequestering a portion of the radionuclide source term. For these reasons there is a need to evaluate the incorporation of Pu and other radionuclides into various Fe-oxide phases, and to understand the behavior of coprecipitated phases during mineral recrystallization processes and during re-oxidation events. Radionuclide coprecipitation with Fe minerals may impact long-term repository performance and is an ongoing research focus at Lawrence Livermore National Laboratory.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Radionuclide Interaction with Hydrothermally Altered Repository Materials (M4SF-23LL010302052)

This progress report (Level 4 Milestone Number M4SF-23LL010302052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Activity Number SF-23LL01030205. The research is focused on actinide and radionuclide sequestration in hydrothermally altered repository materials. In FY23, a manuscript was in preparation for publication summarizing our analysis of radionuclide sorption and coprecipitation into Fe oxide phases and evaluation of radionuclide partitioning values across a range of radionuclides relevant to performance assessment. We demonstrated our approach in detail using Se sorption and coprecipitation with iron oxide minerals. These data were presented in our FY22 annual report and will not be repeated here. We also initiated experiments to identify radionuclide interaction with hydrothermally altered crystalline repository and backfill materials. Recent research performed at Los Alamos National Laboratory (LANL) and Sandia National Laboratory (SNL) has provided key insights regarding the hydrothermal alteration behavior of bentonite backfill in the presence of repository materials (steel, concrete, etc.). We are now examining how mineral alteration affects retardation behavior of plutonium and a suite of other radionuclides. These experiments also allow us to test the predictive ability of our component additivity approach to surface complexation and ion exchange. Our guiding hypothesis is that a robust surface complexation/ion exchange model and associated database, developed using our L-SCIE approach, can effectively predict changes in radionuclide sorption behavior resulting from the hydrothermal alteration of mineralogy in a repository near field. A short update of results to date is presented below. A manuscript was also in preparation describing a self-consistent model and approach to simulating Se(IV) and Se(VI) sorption to 5 iron oxide phases based on our L-SCIE community database. This will be the first implementation of a multi-mineral and multi-oxidation state sorption model using our new L-SCIE database and workflow. A short summary of these results is presented below.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2024

M3SF-24LL010302052-Comprehensive Analysis of Radionuclide Interaction with Hydrothermally Altered Repository Materials

This progress report (Level 3 Milestone Number M3SF-24LL010302052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Work Package Number SF-24LL01030205. The research is focused on actinide and radionuclide sequestration in hydrothermally altered repository materials. In FY24, we completed a rigorous analysis of Se sorption to iron oxide phases using our L-SCIE sorption database. This effort explicitly accounts for surface titration behavior of oxide surfaces that was the subject of a recently published manuscript (Han et al., 2023). With this in mind, our Se sorption analysis now yields a more robust workflow for developing self-consistent surface complexation modeling approaches that can be adapted to specific SCM conceptual and numerical approaches (i.e. non-electrostatic, diffuse layer, triple layer models). In late FY24, we plan to publish the results of our comprehensive surface complexation modeling of Se(IV) and Se(VI) sorption to iron oxide mineral phases and provide a path forward to developing robust radionuclide sorption models for use in performance assessment. In FY24, we also submitted a manuscript summarizing our approach to integrating radionuclide sorption and coprecipitation phenomena and evaluation of radionuclide partitioning values across a range of radionuclides relevant to performance assessment. We demonstrated our approach in detail using Se sorption and coprecipitation with iron oxide minerals as a test case. This manuscript was recently accepted for publication in Applied Geochemistry (Balboni et al., Accepted). We also continued experiments to identify radionuclide interaction with hydrothermally altered crystalline repository and backfill materials. Recent research performed at Los Alamos National Laboratory (LANL) and Sandia National Laboratory (SNL) has provided key insights regarding the hydrothermal alteration behavior of bentonite backfill in the presence of repository materials (steel, concrete, etc.). We are now examining how mineral alteration affects retardation behavior of a suite of radionuclides of interest to repository performance assessment. These experiments also allow us to test the predictive ability of our component additivity approach to surface complexation and ion exchange. Our guiding hypothesis is that a robust surface complexation/ion exchange model and associated database, developed using our L-SCIE approach, can effectively predict changes in radionuclide sorption behavior resulting from the hydrothermal alteration of mineralogy in a repository near field. A short update of results to date is presented below.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2014

CaCO 3 Precipitation, Transport and Sensing in Porous Media with In Situ Generation of Reactants

Ureolytically driven calcite precipitation is a promising approach for inducing subsurface mineral precipitation, but engineered application requires the ability to control and predict precipitate distribution. To study the coupling between reactant transport and precipitate distribution, columns with defined zones of immobilized urease were used to examine the distribution of calcium carbonate precipitation along the flow path, at two different initial flow rates. As expected, with slower flow precipitate was concentrated toward the upstream end of the enzyme zone and with higher flow the solid was more uniformly distributed over the enzyme zone. Under constant hydraulic head conditions the flow rate decreased as precipitates decreased porosity and permeability. The hydrolysis/precipitation zone was expected to become compressed in the upstream direction. However, apparent reductions in the urea hydrolysis rate and changes in the distribution of enzyme activity, possibly due to CaCO 3 precipitate hindering urea transport to the enzyme, or enzyme mobilization, mitigated reaction zone compression. Co-injected strontium was expected to be sequestered by coprecipitation with CaCO 3 , but the results suggested that coprecipitation was not an effective sequestration mechanism in this system. In addition, spectral induced polarization (SIP) was used to monitor the spatial and temporal evolution of the reaction zone.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Stabilized lithium metal oxide electrode material and method of preparation

A stabilized lithium metal oxide cathode material comprises microparticles of lithium metal oxide in which individual particles thereof a core of lithium metal oxide and a coating of a different lithium metal oxide surrounding the core. There is an interface layer between the cores and the coatings in which there are gradients of metal ions in the direction of coating to core. The materials are made by a three stage process involving coprecipitating precursor metal hydroxide core particles at a controlled pH; coprecipitating a different metal hydroxide coating on the particles without controlling the pH; and then calcining the resulting coated precursor particles with lithium hydroxide to form the stabilized lithium metal oxide material.

Lipson, Albert L.↗
DOE OSTI2024

Stabilized lithium metal oxide electrode material and method of preparation

A stabilized lithium metal oxide cathode material comprises microparticles of lithium metal oxide in which individual particles thereof a core of lithium metal oxide and a coating of a different lithium metal oxide surrounding the core. There is an interface layer between the cores and the coatings in which there are gradients of metal ions in the direction of coating to core. The materials are made by a three stage process involving coprecipitating precursor metal hydroxide core particles at a controlled pH; coprecipitating a different metal hydroxide coating on the particles without controlling the pH; and then calcining the resulting coated precursor particles with lithium hydroxide to form the stabilized lithium metal oxide material.

Lipson, Albert L.↗
DOE OSTI2018

Investigation of Superparamagnetism in Microwave and Conventional Processed Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} Nanoparticles

Nanoparticles of spinel cubic Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} are first prepared by the coprecipitation method and then subjected to conventional solid-state sintering and microwave processing techniques. Particle sizes are estimated by field emission scanning electron microscopy (FESEM) to be in the nanometer (5–13 nm) range. Transmission electron microscopy (TEM) also supports the FESEM data. The magnetization measurement by vibration sample magnetometry of the conventionally sintered sample shows a paramagnetic nature at room temperature, a superparamagnetic behaviour at low temperature, and a ferromagnetic nature at even lower temperature. The blocking temperature is estimated to be nearly 110 K. Microwave-processed samples show a superparamagnetic nature even at room temperature. The Fe{sup 3+} cations are found at both the sites confirmed by X-ray photoelectron spectroscopy (XPS), are prepared by microwave processing, and have better magnetic properties as compared to the conventionally sintered particles.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Facile Synthesis of Magnetically Recyclable Fe{sub 2}O{sub 3}–MFe{sub 2}O{sub 4} Photocatalyst from Saprolite-Limonite Laterite Leach Liquors

Photocatalyst degradation is an effective and environment-friendly method for dye pollution. Magnetically recyclable Fe{sub 2}O{sub 3}–MFe{sub 2}O{sub 4} composites were successfully synthesized from laterite leach liquors by a simple coprecipitation-calcination method. The as-prepared samples were characterized by x-ray diffraction (XRD), physical property measurement system (PPMS), and UV-Vis. The results show that the Fe{sub 2}O{sub 3}–MFe{sub 2}O{sub 4} composites can be easily recycled from the solution due to the magnetic properties. Photodegradation experiments results indicated that the degradation rate of rhodamine B (RhB) solution were found to be about 90.0% for the composites, and the degradation rate were still more than 80.0% after being reused for five times. The heterostructure between the Fe{sub 2}O{sub 3} and MFe{sub 2}O{sub 4} effectively enhanced the separation of electron hole pairs, facilitating the photocatalysis process. This paper provided a facile pathway for comprehensive utilization of laterite leach liquor to synthesize magnetically recyclable Fe{sub 2}O{sub 3}–MFe{sub 2}O{sub 4} with enhanced photocatalyst performance.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Effect of Preparation Conditions on the Structure and Magnetic Properties of Metal-Doped Magnesium Ferrites Synthesized From Laterite Leaching Solutions

In this paper, metal-doped magnesium ferrites (MgFe{sub 2}O{sub 4}) were synthesized from laterite leaching solutions using a coprecipitation-calcination method. The as-synthesized samples were characterized by x-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), and physical property measurement system (PPMS) to determine the structure and magnetic properties. The effects of preparation conditions including precipitant reagents and metal ion concentrations in the laterite leaching solutions on the as-prepared spinel ferrites were investigated systematically. It is indicated that Ni–Co–Mn-doped MgFe{sub 2}O{sub 4} and Mn–Al–Cr-doped MgFe{sub 2}O{sub 4} could be synthesized from laterite leaching solutions by using sodium hydroxide (NaOH) and ammonia solution (NH{sub 3}⋅H{sub 2}O) as precipitant reagent, respectively. By adjusting the metal ion concentrations in the laterite leaching solutions, Ni–Co–Mn-doped MgFe{sub 2}O{sub 4} with different substitution contents were obtained. With the Ni and Mn substitution content increasing, the lattice constant and average grain size decreased, while x-ray density increased correspondingly. Magnetic property tests indicated that all the as-prepared samples exhibited typical ferrimagnetic behavior at room temperature, and the saturation magnetization (Ms) depended on the Ni, Co, and Mn substitution content. Specifically, the Ms and Hc values of the as-prepared metal-doped MgFe{sub 2}O{sub 4} sample with optimum substitution content of 0.185 could reach 33.22 emu g{sup −1} and 53 Oe, respectively.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Magnetic and Structural Properties of Novel Neodymium-Tin Spinel Ferrite Nanoparticles

Novel spinel neodymium-tin ferrite nanoparticles (Nd{sub 0.5}Sn{sub 0.5}Fe{sub 2}O{sub 4}) have been synthesized by the coprecipitation method; x-ray diffraction (XRD), transmission electron microscopy (TEM), and superconducting quantum interference device magnetometer (SQUID) techniques were used to characterize the crystal structure, morphology, and magnetic properties. The spinel structure of a single phase is obtained according to XRD results. From TEM characterization results, we obtained a spherical morphology with an average of 13 nm. Magnetic measurement indicates that the nanoparticles have a superparamagnetic phase with a corresponding blocking temperature (T{sub B}) of about 360 K. These new nanomaterials can potentially be used in nanoelectronic devices, magnetic sensors, and hyperthermia application.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2018

Enhancing the Structural and Spectroscopic Properties of Cr{sup 3+} Ion-Doped Ni/Cd/Zn Nanoferrite To Be Applied To Industrial Applications

Nanocrystalline Cr-doped Ni/Cd/Zn of general formula Ni{sub 0.7}Cd{sub 0.1}Zn{sub 0.2}Cr{sub x}Fe{sub 2−x}O{sub 4} (x= 0, 0.1, 0.3, 0.5, 0.7, 1) were synthesized by coprecipitation method. X-ray analysis (XRD) confirmed that the samples had a single-phase cubic spinel structure. The morphology was studied using field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) to assure that the samples were in the nanoscale range. Spectroscopic analysis was carried out using UV-VIS-NIR spectroscopy for all samples. One can conclude that Ni{sub 0.7}Cd{sub 0.1}Zn{sub 0.2}Cr{sub 0.5}Fe{sub 1.5}O{sub 4} had the most suitable energy bandgap that could be applied to the visible light region and many industrial applications. Moreover, this sample (Ni{sub 0.7}Cd{sub 0.1}Zn{sub 0.2}Cr{sub 0.5}Fe{sub 1.5}O{sub 4}) played an important role in the improvement of photocatalytic efficiency.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2019

Influence of the composition on the electrochemical properties of cathode materials {sub x}Li{sub 2}MnO{sub 3}•(1–x)LiMn{sub 1/3}Ni{sub 1/3}Co{sub 1/3}O{sub 2} for lithium-ion batteries

Lithium-rich transition metal complex oxides of the general composition xLi{sub 2}MnO{sub 3}• •(1–x)LiMO{sub 2} (M = Mn{sub a}Ni{sub b}Co{sub c}, a + b + c = 1) were synthesized by coprecipitation and modified Pechini method. The influence of the oxide phase composition on their electrochemical performance as cathode materials was studied in lithium half-cells. Effects of the synthetic approach and synthesis conditions on the morphology and electrochemical characteristics of the materials obtained were considered. The composition 0.35Li{sub 2}MnO{sub 3}• •0.65LiMn{sub 1/3}Ni{sub 1/3}Co{sub 1/3}O{sub 2} demonstrates the highest discharge capacity retention during cycling. The samples with discharge capacity of 290 mA h g{sup –1} were obtained.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Selenium contamination, consequences and remediation techniques in water and soils: A review

Highlights: • Se contamination in environment emerged as a serious threat. • Se causes various several fatal diseases in human beings and animals. • Various treatment techniques for Se removal from water and soil are reviewed. • Adsorption and membrane separation are seemed to be suitable on a commercial scale. • The knowledge gaps to be addressed are proposed. Selenium (Se) contamination in surface and ground water in numerous river basins has become a critical problem worldwide in recent years. The exposure to Se, either direct consumption of Se or indirectly may be fatal to the human health because of its toxicity. The review begins with an introduction of Se chemistry, distribution and health threats, which are essential to the remediation techniques. Then, the review provides the recent and common removal techniques for Se, including reduction techniques, phytoremediation, bioremediation, coagulation-flocculation, electrocoagulation (EC), electrochemical methods, adsorption, coprecipitation, electrokinetics, membrance technology, and chemical precipitation. Removal techniques concentrate on the advantages, drawbacks and the recent achievements of each technique. The review also takes an overall consideration of experimental conditions, comparison criteria and economic aspects.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Photocatalytic property and structural stability of CuAl-based layered double hydroxides

Three types of CuMAl layered double hydroxides (LDHs, M=Mg, Zn, Ni) were successfully synthesized by coprecipitation. Powder X-ray diffraction (XRD), inductively coupled plasma atomic emission spectrometry (ICP-AES) and UV–Vis diffuse reflectance spectrum (UV–vis) were used to confirm the formation of as-synthesized solids with good crystal structure. The photocatalytic activity of those LDH materials for CO{sub 2} reduction under visible light was investigated. The experimental results show that CuNiAl-LDHs with narrowest band gap and largest surface areas behave highest efficiency for methanol generation under visible light compared with CuMgAl-LDHs and CuZnAl-LDHs. The CuNiAL-LDH showed high yield for methanol production i.e. 0.210 mmol/g h, which was high efficient. In addition, the influence of the different M{sup 2+} on the structures and stability of the CuMAl-LDHs was also investigated by analyzing the geometric parameters, electronic arrangement, charge populations, hydrogen-bonding, and binding energies by density functional theory (DFT) analysis. The theoretical calculation results show that the chemical stability of LDH materials followed the order of CuMgAl-LDHs>CuZnAl-LDHs>CuNiAl-LDHs, which is just opposite with the photocatalytic activity and band gaps of three materials. - Graphical abstract: The host–guest calculation models and XRD patterns of CuMAl-LDHs: CuMgAl-LDHs (a), CuZnAl-LDHs (b) and CuNiAl-LDHs (c). - Highlights: • Three types of CuMAl layered double hydroxides (LDHs, M=Mg, Zn, Ni) has been synthesized. • CuMgNi shows narrower band gap and more excellent textural properties than other LDHs. • The band gap: CuMgAl<CuZnAl<CuNiAl based on result from UV–vis analysis. • CuMgAl shows the highest stability and lowest photocatalytic activity, while CuNiAl just opposite.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Constructing MnO{sub 2}/single crystalline ZnO nanorod hybrids with enhanced photocatalytic and antibacterial activity

In order to improve the photocatalytic and antibacterial activity of ZnO nanorods, ZnO nanorods decorated with MnO{sub 2} nanoparticles (MnO{sub 2}/ZnO nanorod hybrids) were prepared by using microwave assisted coprecipitation method under the influence of hydrogen peroxide, and the structure, photocatalytic activity and antibacterial property of the products were studied. Experimental results indicated that MnO{sub 2} nanoparticles are decorated on the surface of single crystalline ZnO nanorods. Moreover, the resultant MnO{sub 2}/ZnO nanorod hybrids have been proven to possess good photocatalytic and antibacterial activity, which their degradated efficiency for Rhodamin B (RhB) is twice as the pure ZnO nanorods. Enhancement for photocatalytic and antibacterial activity is mainly attributed to the low band gap energy and excellent electrochemical properties of MnO{sub 2} nanoparticles. - Graphical abstract: The MnO{sub 2}/single crystalline ZnO nanorods hybrids, which MnO{sub 2} nanoparticles are loaded on the surface of ZnO nanorods, were prepared by the step-by-step precipitation method under the assistance of ammonia and hydrogen peroxide. Display Omitted - Highlights: • MnO{sub 2}/ZnO nanorod hybrids were prepared by the step-by-step assembly method. • Single crystalline ZnO nanorods can be decorated by MnO{sub 2} nanoparticles. • MnO{sub 2}/ZnO nanorod hybrids possess good photocatalytic and antibacterial activity. • MnO{sub 2} can improve the photocatalytic activity of ZnO nanorods under visible light.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Influence of sodium dodecyl sulfate concentration on the photocatalytic activity and dielectric properties of intercalated sodium dodecyl sulfate into Zn–Cd–Al layered double hydroxide

Highlights: • Zn–Cd–Al–LDH–DS were synthesized with different SDS concentrations. • Photocatalytic activity of samples was improved by increasing SDS concentration. • Dielectric response of LDH can be described by anomalous low frequency dispersion. • The dc conductivity values were calculated for Zn–Cd–Al–LDH–DS samples. • ESR spectra exhibited the successful intercalation of DS molecule into LDH gallery. - Abstract: Sodium dodecyl sulfate (SDS) has been successfully intercalated into Zn–Cd–Al–LDH precursor with different SDS concentrations (0.2, 0.3, 0.4, 0.5 and 1 mol L{sup −1}) using the coprecipitation method at (Zn{sup 2+} + Cd{sup 2+})/Al{sup 3+} molar ratio of 13 and pH 8. The structural, morphological, texture and composition properties of the synthesized (Zn–Cd–Al–LDH–DS) nanostructure were investigated using powder X-ray diffraction (PXRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR), respectively. The photocatalytic activity of these materials was developed by increasing the concentration of intercalated SDS. The absorbance spectra have been used to detect an anion in the LDH interlayer before and after the intercalation process, which confirmed the presence of the dodecyl sulfate (DS{sup −}) anion into LDH gallery after intercalation. The anomalous low frequency dispersion (ALFD) has been used to describe the dielectric response of Zn–Cd–Al–LDH–DS nanostructure using the second type of universal power law. At low frequency, the polarization effect of electrodes caused the rising in dielectric constant and loss values. An important result of the dielectric measurements is the calculated dc conductivity values, which are new in dielectric spectroscopy of LDH materials. An important result of the electron spin resonance (ESR) spectra exhibited the successful intercalation of DS molecule into LDH gallery. The g-factor value was affected by the SDS concentration which indicated changes to the environment around the DS molecule in LDH interlayer.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Preparation and characterization of bifunctional dendrimer modified Fe{sub 3}O{sub 4}/CdTe nanoparticles with both luminescent and superparamagnetic properties

Highlights: • The fluorescent superparamagnetic dendrimeric Fe{sub 3}O{sub 4}/CdTe nanoparticles are synthesized in this paper. • The synthesized nanocomposites maintain excellent magnetic properties. • The synthesized nanocomposites maintain highly luminescent markers with narrow emission bands. - Abstract: Magnetic nanoparticles Fe{sub 3}O{sub 4} were prepared by hydrothermal coprecipitation of ferric and ferrous ions using NaOH. The surface modification of Fe{sub 3}O{sub 4} nanoparticle by dendrimers has rendered the nanoparticle surface with enriched amine groups which facilitated the adsorption and conjugation of thioglycolic acid (TGA) modified CdTe quantum dots to form a stable hybrid nanostructure. Three generations (first generation: G0F, second generation: G1F, third generation: G3F) of bifunctional dendrimeric Fe{sub 3}O{sub 4}/CdTe nanoparticles were successfully prepared using this technique and characterized by microscopy. The optical and magnetic properties of the dendrimeric Fe{sub 3}O{sub 4}/CdTe nanoparticle were also investigated. The microscopic study reveals 3 different sizes for 3 generations, 16 nm (G0F), 31 nm (G1F) and 47 nm (G3F). Among three generations of nanoparticles, the G1F has the best optical property with a luminescent quantum yield of 25.6% and the G0F has the best magnetic property with a saturation magnetization of 19.3 emμ/g.

77 NANOSCIENCE AND NANOTECHNOLOGY↗