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A series of [Tb.sup.3+] doped cubic Mg[Al.sub.2][O.sub.4] green phosphors were synthesized via hydrothermal method followed by a post-annealing process. The variation regularity of phase structure, morphology, particle size and concentration quenching mechanism were investigated. The results showed that the crystal structure of matrix materials was not affected when [Tb.sup.3+] ions were introduced. In addition, the micrometer-sized rods and excellent dispersion of the particles were obtained by adding urea. Under excitation at 377 nm, the phosphors exhibited the characteristic of [Tb.sup.3+] emissions with the peaks located at 488 nm ([.sup.5][D.sub.4] [right arrow] [.sup.7][F.sub.6]), 544 nm ([.sup.5][D.sub.4] [right arrow] [.sup.7][F.sub.5]) and 588 nm ([.sup.5][D.sub.4] [right arrow] [.sup.7][F.sub.4]), respectively. Moreover, based on optical analysis, it can be inferred that electric dipole-dipole (d-d) interaction plays an important role in concentration quenching process of [Tb.sup.3+] ions. The green light emitting phosphor Mg[Al.sub.2][O.sub.4]: [Tb.sup.3+] can be realized by adjusting the concentrations of [Tb.sup.3+], and the optimum concentration of [Tb.sup.3+] ions in Mg[Al.sub.2][O.sub.4] was found to be 0.02. Finally, the average fluorescence decay lifetime and the CIE chromaticity coordinates of [Mg.sub.0.98][Al.sub.2][O.sub.4]:0.02[Tb.sup.3+] phosphor were calculated to be 1.2005 ms and (0.3197 0.4109), respectively. The above results suggest that the developed phosphor could have potential to be used as a single-phase green emission phosphor for near-ultraviolet light-emitting diode (NUV-LED) applications., Aluminate-based luminescent materials activated by rare earth ions are of interest due to their good water resistance, stable chemical properties, high efficiency, and lower cost (1-3). As the use of [...]

The NaY[(Mo[O.sub.4]).sub.2]:[Yb.sup.3+]/ [Tm.sup.3+] single crystal was grown by the vertical Bridgman method using spontaneous crystallization. After annealing at 850 [degrees]C for 24 h in a muffle furnace under an air atmosphere, the obtained light black crystal became transparent and optically clear. Powder X-ray diffraction (PXRD) confirmed that the as-grown crystal had the structure of scheelite. The segregation coefficients of [Tm.sup.3+] and [Yb.sup.3+] were 0.589 and 0.588, respectively. Under 980 nm excitation, the temperature dependence of the emission intensity of the crystal in the temperature range of 298-473 K was measured. The results show that, because of the thermal quenching effect, the emission intensity decreases as the temperature rises. The possible energy transfer modes between [Yb.sup.3+] and [Tm.sup.3+] ions were analyzed. The emission cross section was calculated to be 1.97 x [10.sup.-20] [cm.sup.2] by the Fuchtabauer-Ladeburg formula, and the fluorescence lifetime was fitted to be 166.67 [micro]s., In recent years, with the rapid development of near-infrared (NIR) optical amplifiers and mid-IR fiber lasers, new rare earth-doped solid IR luminescent materials have attracted great attention (1-5). Among rare [...]

This work aims at studying the mechanism involved in the phase coarsening of ternary tri-continuous polymer blends. To this aim, the phase coarsening behaviors of a co-continuous polyethylene (PE)/polyethylene oxide (PEO) blend, and a tri-continuous PE/polycaprolactone (PCL)/PEO blend during the quiescent annealing process are studied. Rheological characterization showed that the zero-shear viscosities of PE and PCL phases were similar but much less than the zero-shear viscosity of the PEO phase. The evolution of the microstructure of the blends during annealing was characterized using a characteristic length scale ([lambda]). It was found that [lambda] in both co- and tri-continuous blends increased linearly in the early stages of annealing but the phase coarsening rate decreased in both systems at longer annealing times. In general, the tri-continuous blend showed much faster phase coarsening rate. The effects of kinetic and thermodynamic parameters on the observed phase coarsening behaviors are discussed in detail. A new lubricating mechanism is proposed in which the deformation of the PCL layer between PE and PEO phases reduces the effect of high viscosity of the PEO phase and increases the phase coarsening rate in ternary blends. The obtained results provide a new insight into the role of the middle layer in tri-continuous polymer blends on controlling the phase morphology of these systems. KEYWORDS annealing, blends, morphology, phase coarsening, tri-continuous, 1 | INTRODUCTION The wide range of properties and high design flexibility of binary polymeric systems provides a unique tool in designing polymeric systems with a desired set of properties. [...]

In this work, we present a solvothermal method for the synthesis of hematite thin films on fluorine-doped tin oxide substrates. This simple method uses a precursor solution of iron(III) 2,4-pentanedionate dissolved in ethanol with a microliter-scale amount of water and yields hematite ~500 nm thick films after annealing. The synthesized films were characterized using an array of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance, and powder X-ray diffraction. Incorporating water into the precursor solution provides nucleation sites for the reaction and results show that by altering the amount of water used in the synthesis, it is possible to generate nanocrystalline films of different morphologies, nanocrystal size distributions, and surface areas. This synthetic procedure therefore provides control over the films' physical and electrochemical characteristics. Doping of hematite thin films is also possible using this synthesis, as exemplified by doping with tin by adding tin(II) 2,4-pentanedionate to the precursor solution. To demonstrate utility, we build prototype photoelectrochemical cells using the synthesized hematite as the photoanode. Key words: solvothermal synthesis, photoanodes, hematite, nanostructures, thin films. Dans le cadre des presents travaux, nous presentons une methode solvothermale pour la synthese de couches minces d'hematite sur des substrats d'oxyde d'etain dopes au fluor. Cette methode simple consiste a utiliser une solution du precurseur 2,4-pentanedionate de fer (III) dissous dans de l'ethanol contenant une quantite d'eau de l'ordre du micro litre pour produire des couches d'hematite d'une epaisseur de 500 nm apres recuit. Nous avons caracterise les couches ainsi synthetisees a l'aide d'une serie de methodes, notamment la microscopie electronique a balayage, la spectroscopie de rayons X a dispersion d'energie, la spectroscopie de reflectance diffuse et la diffraction des rayons X sur poudre. L'incorporation de l'eau dans la solution du precurseur offre des sites de nucleation pour la reaction. En effet, les resultats montrent qu'en modifiant la quantite d'eau utilisee dans la synthese, il est possible de generer des couches nanocristallines de differentes morphologies, dont la surface et la distribution de la taille des nanocristaux varient. Cette methode de synthese permet donc de moduler les caracteristiques physiques et electrochimiques des couches. Il est egalement possible de doper les couches minces d'hematite en utilisant cette synthese, comme nous l'avons illustre par l'exemple du dopage avec l'etain en ajoutant du 2,4-pentanedionate d'etain (II) a la solution de precurseur. Pour demontrer l'utilite de cette methode, nous avons realise des prototypes de cellules photoelectrochimiques a l'aide de l'hematite que nous avons synthetisee comme la photoanode. [Traduit par la Redaction] Mots-cles : synthese solvothermale, photoanodes, hematite, nanostructures, couches minces., Introduction Nanostructured architectures are often desired for applications involving surface-mediated events such as sensing, (1-3) energy conversion and storage devices, (4,5) and catalysis. (6-8) Several approaches such as templating (9,10) [...]

The unknown cooling-rate history of natural silicate melts can be investigated using differential scanning heat capacity measurements together with the limiting fictive temperature analysis calculation. There are a range of processes occurring during cooling and re-heating of natural samples which influence the calculation of the limiting fictive temperature and, therefore, the calculated cooling-rate of the sample. These processes occur at the extremes of slow cooling and fast quenching. The annealing of a sample at a temperature below the glass transition temperature upon cooling results in the subsequent determination of cooling-rates which are up to orders of magnitude too low. In contrast, the internal stresses associated with the faster cooling of obsidian in air result in an added exothermic signal in the heat capacity trace which results in an overestimation of cooling-rate. To calculate cooling-rate of glass using the fictive temperature method, it is necessary to create a calibration curve determined using known cooling- and heating-rates. The calculated unknown cooling-rate of the sample is affected by the magnitude of mismatch between the original cooling-rate and the laboratory heating-rate when using the matched cooling-/heating-rate method to derive a fictive temperature/cooling-rate calibration curve. Cooling-rates slower than the laboratory heating-rate will be overestimated, while cooling-rates faster than the laboratory heating-rate are underestimated. Each of these sources of error in the calculation of cooling-rate of glass materials-annealing, stress release and matched cooling/heating-rate calibration-can affect the calculated cooling-rate by factor of 10 or more., Author(s): Sharon L. Webb [sup.1] Author Affiliations: (1) grid.7450.6, 0000 0001 2364 4210, Mineralogy Department, Georg-August University, , Goettingen, Germany Introduction The cooling-rate history of silicate melts can be investigated [...]

This paper investigates a practical batching decision problem that arises in the batch annealing operations in the cold rolling stage of steel production faced by most large iron and steel [...]

This article presents a broad overview of key annealing processes such as recovery, recrystallization, and grain growth in magnesium and its alloys. Magnesium and its alloys are receiving alot of [...]

In the setup for nonmelt laser spike anneal (LSA), the wafer is mounted with the front-side facing the laser beam and backside facing the heated hotplate. When arsenic or phosphorus-implanted silicon is subjected to LSA, sheet resistance degradation, indicative of dopant deactivation, is observed when the post-LSA thermal budget provided by the heated chuck (hotplate) is increased. This additional thermal budget is associated with the chuck temperature and duration a wafer is left on the chuck after LSA. The deactivation is believed to occur due to the ineffective removal of implantation damage by LSA, giving rise to the release of point defects during the post-LSA thermal cycle that aids inactive clusters formation. The observed phenomena severely degrades the within wafer uniformity since LSA is a localized heating process that relies on scanning the laser beam across the whole wafer. As such, different portions of the implanted silicon wafer will remain on the hotplate for varying durations depending on when the laser beam scans through a particular spot. By adopting a dual step source/drain anneal scheme that incorporates a spike rapid thermal annealing condition sufficient to anneal out the implantation damage prior to LSA, the within wafer nonuniformity issue can be rectified. Index Terms--Ion implantation, laser annealing, p-n junctions, resistance, semiconductor materials.

Bipolar test structures were irradiated and annealed with various combinations of molecular hydrogen gas ambients, bias, and thermal conditions. The results show that the buildup and annealing behavior of defects in bipolar base oxides depend strongly on hydrogen concentration. Differences observed in trapped oxide charge annealing rates suggest that the charged defects created in hydrogen-rich environments may be attributed to different types of positive charge in addition to trapped holes. Index Terms--Bipolar oxide, gated bipolar devices, interface traps, hydrogen, oxide trapped charge, radiation-induced.

From annealing experiments performed on both irradiated Si[O.sub.2]--Si structures and MOS devices, swift heavy ions-induced morphological oxide defects are proposed to possibly act as latent defects. Index Terms--Heavy ion, isochronal annealing, latent defects, MOS devices, reliability, Si[O.sub.2]2, structural modifications.

An effective way of annealing in vacuum is described for enhancing the Q-Factor of planar spiral inductors for radio frequency (RF) applications and the impact of the enhancement of the Q is analyzed. The decrease in substrate resistance for an annealed inductor has a negative affect on Q enhancement and the final increment of the Q-Factor by annealing has shown the contribution of the copper coil to be dominant.

A process for self-pinning of AuSi eutectic alloy droplets to a Si substrate is described that is induced by a controlled temperature annealing in ultrahigh vacuum. Phase separation is observed upon cooling of the droplets, which has led to the formation of amorphous Si-rich channels within the core and the formation of crystalline Si nanoshells on the outside.

Annealing Monte Carlo simulations were carried to study the self-assembly of the cylinder forming [A.sub.13][B.sub.3][C.sub.2] triblock terpolymer in cylindrical nanopores. A neutral pore wall had alternating helix and partial cylinder structures on the outside layer, whereas various surface structures were seen when the pore wall attracted shorter blocks.

The nucleation and growth behavior of sol-gel-derived lead zirconate titanate (PZT) films at different rapid thermal annealing (RTA) conditions were examined. Higher heating rates led to dense microstructures, smooth surfaces and better film ferroelectric properties.

The effect of dopant profile engineering on planar MOSFETs fabricated using laser spike annealing (LSA) activation is examined. Results suggest 10 percent improvement in device performance as compared to conventional LSA devices.

Stochastic continuation (SC) algorithm is a new class of hybrid algorithm that combines simulated annealing with deterministic continuation. The article describes the capability of the SC algorithm in outperforming standard simulated annealing.

The electrical and interfacial characteristics of MOS capacitors with atomic layer deposited (ALD) Al2O3, HfO2 and HfAIO gate dielectrics on sulfur-passivated GaAs substrates are examined. Results suggest the exhibition of good electrical properties by HfAIO on p-type GaAs due to postdielectric annealing (PDA) at 500 degree C.

This paper presents a study of the gamma-ray induced radiation damage effect in large size (2.5 x 2.5 x 20 [cm.sup.3]) LSO and LYSO crystal samples. Optical and scintillation properties, including longitudinal transmittance and photo-luminescence spectra, light output and light response uniformity with PMT and APD readout, are measured before and after [gamma]-ray irradiations with an integrated dose up to 106 rad for three LSO and LYSO samples from different vendors. It was found that 300[degrees]C thermal annealing removes all radiation induced absorption. The photo-luminescence spectra measured before and after the irradiations were found to be consistent, indicating that the scintillation mechanism is not damaged. The radiation damage recovers very slow under the room temperature, indicating that the radiation damage level in LSO and LYSO crystals is not dose rate dependent. It was also found that the overall radiation damage in LSO and LYSO crystals is small as compared to other crystal scintillators commonly used in high energy and nuclear physics experiments. Index Terms--Crystal, light output, lutetium oxyorthosilicate, lutetium yttrium oxyorthosflicate, photo-luminescence, radiation damage, scintillator, transmission.

A silicon CCD imager has been irradiated with 10 MeV protons and measurements focused on Random Telegraph Signal (RTS). A variance detection method is applied for quantifying the number of RTS after irradiation and through isochronal annealing. The observed behavior is analyzed and corresponds to the annealing of phosphorus-vacancies. Index Terms--Annealing, CCD, irradiation, proton.