Target Preparation Research Articles

An (ultra) high-vacuum compatible sputter source for oxide thin film growth

A miniaturised CF-38 mountable sputter source for oxide and metal thin film preparation with enhanced high-vacuum and ultra-high-vacuum compatibility is described. The all home-built sputtering deposition device allows a high flexibility also in oxidic sputter materials, suitable deposition rates for preparation of films in the nm- and the sub-monolayer regime and excellent reliability and enhanced cleanliness for usage in UHV chambers. For a number of technologically important--yet hardly volatile--materials, the described source represents a significant improvement over thermal deposition techniques like electron-beam- or thermal evaporation, as especially the latter are no adequate tool to prepare atomically clean layers of refractory oxide materials. Furthermore, it is superior to commercially available magnetron sputter devices, especially for applications, where highly reproducible sub-monolayer thin film preparation under very clean UHV conditions is required (e.g., for studying phase boundary effects in catalysis). The device in turn offers the usage of a wide selection of evaporation materials and special target preparation procedures also allow the usage of pressed oxide powder targets. To prove the performance of the sputter-source, test preparations with technologically relevant oxide components, comprising ZrO2 and yttrium-stabilized ZrO2, have been carried out. A wide range of characterization methods (electron microscopy, X-ray photoelectron spectroscopy, low-energy ion scattering, atomic force microscopy, and catalytic testing) were applied to demonstrate the properties of the sputter-deposited thin film systems.

Preparation of isotopic antimony targets

Thin self-supporting 123Sb targets were needed for studies using GAMMASPHERE investigating transverse wobbling in the highly-deformed triaxial nucleus 135Pr. The experiment was carried out using the 123Sb(16O,4n)135Pr reaction with the 80 MeV 16O beam provided by the ATLAS accelerator facility. In particle–particle coincidence measurements 121Sb targets were irradiated with a 332 MeV 28Si beam from ATLAS to measure evaporation residues and fission. The antimony targets were prepared self-supporting by the method of physical vapor deposition onto polished glass substrates or on various backing materials. Target thicknesses on the order of 500–1,000 μg/cm2 were obtained and used for the experiments. Details of the target production and performance in beam will be discussed.

Modified sol–gel preparation of LiNbO3 target for PLD

When preparing LiNbO3 thin layer by PLD, the maximal density of polycrystalline target is important. In this work, we prepared the precursor powders by sol–gel method and used them at PLD target synthesis. The gels were synthesized by Pechini polyesterification, using citric acid and ethylene glycol as an organic matrix constituents, and then decomposed using various temperatures (800, 600 and 400°C) and atmospheres (air, nitrogen and oxygen in sequence). Out of several combinations tested, the decomposition at 800°C in nitrogen followed by the oxidation at 400°C in oxygen was found to be the best way to achieve the minimal particle size of powder precursor resulting in denser targets. The prepared targets were characterized by XRD and SEM.The optimized process was subsequently used for preparation of LiNbO3 target. Thin layers prepared by PLD from this target resulted smoother than the layers prepared from commercial monocrystalline target.

68Ge/68Ga production revisited: excitation curves, target preparation and chemical separation – purification

SummaryTargets withstanding high beam power for production of68Ge by proton irradiation of Ga were developed using electrodeposition of Ga/Ni alloy (70/30%) on thick Cu backings. Cross sections for reactions, induced by protons (up to 36MeV) and deuterons (up to 50MeV), producing γ-emitting radioisotopes with half-lives longer than 2 h were measured in a stacked-foil irradiation using thin Ga/Ni targets produced with this technique. Excitation functions for68,69Ge are discussed, relative to the monitor reactionsnatCu(p, x)62Zn ornatAl(d, x)24,22Na. The results are compared to the scarce literature values. From derived thick target yields, optimal energy domain and batch yields for68Ge production were calculated and contamination (from69Ge and71Ge) is discussed. A PC-controlled, automated dissolution and separation chemistry set-up for delivery of nca69Ge was developed (yield about 90%) and implemented in an industrial system ready to be mounted in a hot cell.

Preparation of 240Pu and 242Pu targets to improve cross-section measurements for advanced reactors and fuel cycles

240Pu and 242Pu targets were prepared by the so-called “molecular plating” on an Al backing for cross-section measurements. The total activity of the actinide layer was determined by low-geometry alpha-particle counting. The atomic abundances of the two Pu materials were determined via thermal ionization mass spectrometry. A radiochemical separation was performed by anion exchange prior to the preparation of the layers to prevent interferences with the ingrown daughter nuclide during the characterization and cross-section measurements. The targets were prepared to be used in the project “Metrology for New Generation Nuclear Power Plants” (MetroFission), within the frame of the European Metrology Research Programme, directed to improve the knowledge on neutron cross sections through metrological approaches. For measurements of the 240Pu(n,f) and 242Pu(n,f) cross sections 240Pu and 242Pu targets were produced and mounted in fission chambers. In parallel, 240Pu and 242Pu targets were prepared for the ANDES project (Accurate Nuclear Data for Nuclear Energy Sustainability) for cross-section measurements at the CERN neutron time-of-flight facility n_TOF, and the Van de Graaff laboratories of IRMM and CNRS/CENBG.

Effect of laser radiation on multi-wall carbon nanotubes: study of shell structure and immobilization process

Multi-wall carbon nanotubes (MWCNTs) with diameters between 10 and 15 nm were transferred and immobilized onto SiO2 glass substrates by ultraviolet matrix assisted pulsed laser evaporation (UV-MAPLE). Toluene was chosen as solvent material for the preparation of the composite MAPLE targets. An UV KrF* (λ = 248 nm, τ FWHM ≅ 25 ns, ν = 10 Hz) excimer laser source was used for the irradiation experiments. The effects of incident laser fluence on the structure of the laser transferred MWCNTs was investigated by high resolution transmission electron microscopy and Raman spectroscopy. The surface morphology of the laser processed MWCNTs was investigated by field emission scanning electron microscopy and atomic force microscopy in acoustic (dynamic) configuration. Network-like structures constituted by individual nanotubes and nanotube bundles were created onto solid substrates. Changes in the nanotubes’ shell structure can be induced through the tuning of the laser fluence value incident onto the composite MAPLE targets.

Preparation of actinide targets for the synthesis of the heaviest elements

The heaviest elements are synthesized in heavy-ion induced hot fusion reactions with various actinide targets. Because the actinide material is often available only in very limited amounts, a deposition method with high yields (~90 %) is needed. We report on the production of 244Pu, 243Am, 248Cm, 249Bk, and 249Cf targets on thin Ti backings by molecular plating. Different chemical purification steps using ion chromatographic techniques were applied for the purification of 249Cf and 244Pu. The deposition procedure applied for the production of ~0.4–0.8 mg/cm2 thick targets is described. The deposition yield was determined either by α-particle or γ-ray spectroscopy. Furthermore, neutron activation analysis has been applied in the case of 244Pu, 243Am, and 248Cm. Information about the spatial distribution and homogeneity of the target layer was obtained by radiographic imaging.

Preparation of thin stable erbium target sandwiched between carbon layers

Targets of isotopically enriched 170Er (erbium) were prepared on 45 μg/cm2 carbon backing using the method of vacuum evaporation. Another layer of carbon with thickness 23 μg/cm2 was deposited on it as a protective cap with the help of an electron gun. Carbon backing, Er and the capping carbon layer were deposited using resistive heating and electron gun deposition without disturbing the vacuum. The thickness of 170Er was measured by X-ray fluorescence analysis as well as with Rutherford backscattering spectrometry and it was found to be 150 μg/cm2. Successful preparation of sandwiched targets was very sensitive to substrate temperature, deposition rate, duration of in situ annealing, cooling rate etc.

Tritium and Ignition Target Management at the National Ignition Facility

Isotopic mixtures of hydrogen constitute the basic fuel for fusion targets of the National Ignition Facility (NIF). A typical NIF fusion target shot requires approximately 0.5 mmoles of hydrogen gas and as much as 750 GBq (20 Ci) of 3H. Isotopic mix ratios are specified according to the experimental shot/test plan and the associated test objectives. The hydrogen isotopic concentrations, absolute amounts, gas purity, configuration of the target, and the physical configuration of the NIF facility are all parameters and conditions that must be managed to ensure the quality and safety of operations. An essential and key step in the preparation of an ignition target is the formation of a ~60 μm thick hydrogen "ice" layer on the inner surface of the target capsule. The Cryogenic Target Positioning System (Cryo-Tarpos) provides gas handling, cyro-cooling, x-ray imaging systems, and related instrumentation to control the volumes and temperatures of the multiphase (solid, liquid, and gas) hydrogen as the gas is condensed to liquid, admitted to the capsule, and frozen as a single spherical crystal of hydrogen in the capsule. The hydrogen fuel gas is prepared in discrete 1.7 cc aliquots in the LLNL Tritium Facility for each ignition shot. Post-shot hydrogen gas is recovered in the NIF Tritium Processing System (TPS). Gas handling systems, instrumentation and analytic equipment, material accounting information systems, and the shot planning systems must work together to ensure that operational and safety requirements are met.

Comparative study on mathematical set-based drug release kinetics method and kalman filter method applied in evaluating drug release of multi-component traditional Chinese medicine preparations

To provide a mathematical set-based method for evaluating drug release kinetics of multi-component traditional Chinese medicine preparations. With Fuzheng Huayu prescription as the study model, a mathematical set-based method for evaluating drug release kinetics was established to guide the preparation of drug release system of Fuzheng Huayu prescription, and a quantitative evaluation was made for its multi-component drug release characteristics. Its accuracy was verified by Kalman filtering method. The comparison between the two showed that the sample No. 4 of Fuzheng Huayu drug release system showed synchronized drug release with its reference preparation Fuzheng Huayu capsules. The results verified the accuracy and rationality of the evaluation method based on mathematics set. Meanwhile, it displayed the release of target preparations according to asynchronous coefficient (k) and other parameters, and found the orientation of regulating and improving the unit drug release dosage from relevant error parameters of various characteristic peak information, in order to purposefully regulate relevant components, and enable target preparations to meet the synchronized drug release requirements of the reference preparation. Meanwhile, it provided an effective measure for evaluating the quantitative characterization and synchronized release behavior of multi-component traditional Chinese medicines.

X-Ray Computed Tomography as Supporting Technology in The Failure Analysis of Press-In Connections for Electronic Assemblies

Abstract Besides its original field of application–the characterization of microstructures–the metallography is often referred to when analyzing failures of electronic components and assemblies. In this context, the cause of the failure is analyzed by means of a metallographic section. At this point, the precondition and difficulty is the right choice of the section plane. If it is not optimally selected, there is a risk of overlooking the defect and therefore of not recognizing important correlations. The X-ray computed tomography is an efficient method which helps making the right choice and facilitates a targeted metallographic preparation. Conspicuous features inside the damaged component can be detected in advance by means of a three-dimensional volume model established by computed tomography. Based on this information, an appropriate cutting plane can be chosen in the volume model and a targeted metallographic section can be prepared. In the following, it is possible to view the conspicuous spot with high resolution and to analyze its microstructure in selected areas. In order to demonstrate the use of computed tomography as a supporting technology in the target preparation, the following article establishes a link between both testing technologies and their application to the press-fit technology which serves as joining technology when assembling electronic components.

Quest for triorganotin(IV) compounds containing three C,N- and N,C,N-chelating ligands

Three novel tetraorganotin(IV) compounds of general formula L3SnR [where i) L is LCN 2-(N,N-dimethylaminomethyl)phenyl- and R = n-Bu (1), Ph (2); and ii) L is LNCN 2,6-bis-(N,N-dimethylaminomethyl)phenyl- with R = n-Bu (3)] were synthesized. These species were used as potential precursors for the target preparation of some triorganotin(IV) species of general formula L3SnX [where i) L is LNCN with X = OH (4), and ii) L is LCN and X = Br (5), F (5b), Cl (5c)]. Several methods were applied to reach the target L3SnX molecules including the reactions of 1 or 2 with bromine, iodine or hydrohalic acids in various media, Kocheshkov reactions or transmetallation with HgCl2, but the composition of all reaction mixtures was not satisfactory towards the target. Compound 4 has the monomeric structure with OH group interacting with one of the nitrogen atoms via H-bridge. Target compound 5 was prepared by the reaction of three equivalents L4CNSn with SnBr4 followed by the isolation of 5 from the reaction mixture based on different solubility of 5 in various solvents. Surprisingly, the presumably air-stable 5 can easily ionize in the air to give a novel aqua-complex [L3CNSn(H2O)]+Br− (5a). All prepared organotin(IV) compounds bearing both LCN and LNCN ligands were characterized by multinuclear NMR spectroscopy and, when eligible, by the elemental analysis. In addition, the solid-state structures of 1, 2, 4, 5a, 6, 8 and 9 were determined by the X-ray diffraction analysis.

Electron microscope verification of prebreakdown-inducing α-FeSi2 needles in multicrystalline silicon solar cells

It had been shown already earlier by X-ray microanalysis that, in positions of defect-induced junction breakdown in industrial multicrystalline (mc) silicon solar cells, iron-containing precipitates may exist. However, the nature of these precipitates was unknown so far. Here, in such positions, scanning transmission electron microscopy was performed after defect-controlled focused ion beam preparation. First of all, the defect site was localized by microscopic reverse-bias electroluminescence imaging. The high accuracy of following FIB target preparation (<0.1 μm necessary) was obtained by both, electron beam-induced current imaging and secondary electron material contrast observation during the slice-by-slice milling of the TEM specimen. By nano-beam electron diffraction (NBED) and energy dispersive spectroscopy, the iron-containing precipitates were identified as α-type FeSi2 needles, about 30 nm in diameter and several μm in length. The FeSi2 needles show preferential orientation relationships to the silicon matrix and are located in terraced large-angle grain boundaries. Elaborate nano-beam electron diffraction investigation of the FeSi2 revealed orientation relationships of the precipitate to the silicon, which confirm earlier investigations on monocrystalline material. A model explaining the defect-induced breakdown mechanism due to rod-like α-FeSi2 precipitates is presented.

Crystalline nanostructured Cu doped ZnO thin films grown at room temperature by pulsed laser deposition technique and their characterization

We report structural and optical properties of Cu doped ZnO (ZnO:Cu) thin films deposited on glass substrate at room temperature by pulsed laser deposition (PLD) method without pre and post annealing contrary to all previous reports. For preparation of (ZnO:Cu) composites pure Zn and Cu targets in special geometrical arrangements were exposed to 248nm radiations generated by KrF exciter laser. The laser energy was 200mJ with 10Hz frequency and 20ns pulse width. The effect of Cu concentration on crystal structure, morphology, and optical properties were investigated by XRD, FESEM and photoluminescence spectrometer respectively. A systematic shift in ZnO (002) peak with Cu concentration observed in XRD spectra demonstrated that Cu ion has been incorporated in ZnO lattice. Uniform film with narrow size range grains were observed in FESEM images. The photoluminescence (PL) spectra measured at room temperature revealed a systematic red shift in ZnO emission peak and decrease in the band gap with the increase in Cu concentration. These results entail that PLD technique can be realized to deposit high quality crystalline ZnO and ZnO:Cu thin films without pre and post heat treatment which is normally practiced worldwide for such structures.

Effect Of Budgeting Participation To Justice Organization, Organizational Commitment And Organizational Performance In Papua Hospital

In the framework of the implementation of special autonomy for Papua Province, one factor that concerns many people is a matter of budgeting that is often lacking in accordance with the needs of each regency / municipality in the province of Papua. This happens due to the lack of participation of various parties associated with the preparation of the budget in the area when preparing the budget. Another factor that may be the cause is the reluctance of the executive budget to follow the budget that has been set by the finance department. Another possibility is that the budget has been set too difficult to implement due to the preparation of the budget target is too high or too small to reach the target .This study aimed to examine whether there is the influence of participatory budgeting on organizational justice, organizational commitment and performance. The research was conducted in the province of Papua by sampling nine District General Hospital. The method of analysis used was Partial Least Square (PLS). The results of the analysis show that: (1) there is the influence of participatory budgeting to organizational justice and organizational performance, the higher the participatory budgeting, it could lead to higher the fairness and performance of the organization, (2) there is the influence of organizational justice on organizational commitment and organizational performance, the high organizational justice it will result in the higher organizational commitment and organizational performance, and (3) there is the influence of the organization's commitment to organizational performance, the higher the organizational commitment will lead to the higher performance of the organization. Suggestions that can be presented in this study is that the government can do in terms of policy formulation budgeting involves employees at a lower level and the community so as to improve the performance of hospitals. In this research, budgeting participation affect perceptions of organizational justice, and the creation of organizational commitment, which directly or I. Background In the framework of the implementation of special autonomy for Papua Province, one factor that concerns many people is a matter of budgeting that is often lacking in accordance with the needs of each regency / municipality in the province of Papua. This may have been due to the lack of participation of various parties associated with the preparation of the budget in the area when preparing the budget. Another factor that may be the cause is the reluctance of the executive budget to follow the budget that has been set by the finance department. Another possibility is that the budget has been set too difficult to implement due to the preparation of the budget target is too high or too small to reach the target. Budgets in the public sector related to the process of determining the allocation of funds for each program and activity dala monetary units have the people who use the funds. This is the difference with sawsta sector budget because it relates to the allocation of funds from the public. In the public sector organizational funding comes from local taxes and charges, profit regional or state-owned enterprises, government borrowing and debt in the form of government bonds, as well as other funding sources are legitimate and not contrary to the laws and regulations that have been set. Participation in budgeting is a process whereby an individual whose performance is evaluated and awarded based on the achievement of budget targets. That participation has become an integral part of quality of work, quality control, procurement employee option plan and design a new plant. The success of the program budget is primarily determined by the way of making the budget itself. Thus the human factor becomes an important part of budgeting. Man who set goals and objectives, it is also responsible for achieving the goals and targets set. Human behavior as individuals and groups to influence the preparation of the budget and the budget should be to influence the behavior of individuals and groups. Along with the decentralized system of government which gives freedom to the regions to manage their own country, then the budgetary procedure starting from the bottom (bottom up). Budgeting procedure starts from the budget proposals made by the Task Force in the District / City based programs / activities that have been planned. The proposal was referred to the Budget Plan daearah Work Unit and addressed to the

Preparation of ITO Target by Molecular Dynamics Simulation with Normal Pressure Sintering Method

The volume change of ITO target sintering at different temperature of 1673K,1773K,1793K,1823K,1853K and 1873K were investigated by means of molecular dynamics simulation. The experimental results revealed that the rate of reduction in bulk was very fast in prior period of ITO green sintering process, and it was slow in later period. The atomic model of ITO green got the smallest value of 890.918nm3 at the 1853K, and the ITO green can receive the highest densification at this temperature. The simulation results can provide theoretical direction for ITO target normal pressure sintering method.

Preparation of Al-doped ZnO Sputtering Target for Transparent Conductive Films by Pulse-Current Sintering

Preparation of Al-doped ZnO Sputtering Target for Transparent Conductive Films by Pulse-Current Sintering

Release of iodine from organic matter in natural water by K2S2O8oxidation for129I determination

Accelerator mass spectrometry is the only method for measuring 129I in low level environmental samples. In this method, it is essential to convert organic associated iodine into inorganic form for the determination of total 129I or organic 129I because AgI is usually adopted as a target for AMS measurement of 129I. The chemical oxidative method to release iodine from organic matter in natural water was investigated using anion exchange chromatography and CHCl3 extraction methods. K2S2O8 was confirmed to be an ideal oxidative reagent for decomposing organic matters and converting organic iodine to inorganic form. More than 95% of iodine in natural water can be separated by solvent extraction after oxidation under optimal conditions, and the isotopic exchange of iodine in inorganic and organic forms was well completed during the oxidation, being able to result in an identical 129I/127I ratio as in the original water. Our works indicate that the reported chemical oxidation method is a suitable approach for releasing organic associated iodine in natural water to allow separation of iodine and preparation of the AgI target for AMS measurement.

激光加速实验超薄类金刚石碳靶的制备

激光加速实验超薄类金刚石碳靶的制备

Structural Analysis of Longitudinal Si–C–N Precipitates in Multicrystalline Silicon

During crystallization of multicrystalline silicon, carbon-rich liquid-solid phase-boundary layers appear, resulting in precipitation of n-type conductive Si-C-N filaments. We present an in-depth structural analysis of distinct types of filaments to support modeling of their growth. Phase-contrast microtomography down to the submicron level is used to study morphology and seeding of precipitates while still embedded in fully functional solar cell samples. A detailed transmission electron microscopy analysis and a quantitative electron energy loss spectroscopy analysis are presented, based on tomography-assisted target preparation.