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Many polymers exhibit much steeper temperature dependence of their structural relaxation time (higher fragility) than liquids of small molecules, and the mechanism of this unusually high fragility in polymers remains a puzzle. To reveal additional hints for understanding the underlying mechanism, we analyzed correlation of many properties of polymers to their fragility on example of model polymer polystyrene with various molecular weights (MWs). We demonstrate that these correlations work for short chains (oligomers), but fail progressively with increase in MW. Our surprising discovery is that the steepness of the temperature dependence (fragility) of the viscosity that is determined by chain relaxation follows the correlations at all molecular weights. These results suggest that the molecular level relaxation still follows the behavior usual for small molecules even in polymers, and its fragility (chain fragility) falls in the range usual for molecular liquids. It is the segmental relaxation that has this unusually high fragility. We speculate that many polymers cannot reach an ergodic state on the time scale of segmental dynamics due to chain connectivity and rigidity. This leads to sharper decrease in accessible configurational entropy upon cooling and results in steeper temperature dependence of segmental relaxation. The proposed scenario provides a new important insight into the specifics of polymer dynamics: the role of ergodicity time and length scale. At the end, we suggest that a similar scenario can be applicable also to other molecular systems with slow intra-molecular degrees of freedom and to chemically complex systems where the time scale of chemical fluctuations can be longer than the time scale of structural relaxation.

H‐301 tubes for thermal cracking heater were subjected to metallurgical analysis on 2nd October 2007. Results of this analysis indicate that these tubes are of ASTM A355P5 specification. A hard oxide layer formed on the outer surface that is exposed to high temperature and the hardness value on this surface was 250 HB30. The hardness value of other part of the metal was 128.5 HB30. The inner surface was deposited with by‐product of cracking process. The tube expanded in the direction of tube axis causing a little bend to this tube. The change in metal thickness was considered insignificant. Difference in hardness between exposed and new tube was only 10 HB30, which means that the difference in mechanical properties between these tubes were very small. According to the class of damage, the microstructure is still in the class between C and D. This means that only 2.5%—10% of life fraction the material has been consumed. Thus, the remaining life of the tube is about 90%. Based on these results, the tube still may be used for another 10 to 15 years if operating temperatures are in the recommended ranges (400–550°C).

The corrosion inhibition of aluminum and its alloys is the subject of remarkable technological importance due to their increased industrial applications. This paper reports the results of the corrosion inhibition properties of AA6061 and AA6063 aluminum alloys in tropical seawater using sodium benzoate as an inhibitor. It was found that the corrosion inhibition occurred through the adsorption on the surfactant on the metal surface without modifying the mechanism of corrosion processes.

1g chitosan was dissolved in l00 mL of 1% acetic acid solution to prepare a chitosan acetate solution. The solution was then mixed with oleic acid. This chitosan acetate‐oleic acid was then made into thin film by the solution cast technique. The conductivity of the samples was measured from ambient to elevated temperature. The highest conductivity of the chitosan‐salt with 10 wt % oleic acid (OA) at room temperature was 8.35×10−9 Scm−1. The addition of OA has increased the dielectric constant, which implies the increase of dissociation of the salt thereby producing more free ions for conducting and hence increases the ionic conductivity.

We illustrate the optimization of the growth of multi‐wall carbon nanotubes (MWCNTs) using thermal chemical vapor deposition (CVD). Palm‐based dihydrostearic acid (DHSA) which was never been reported as a precursor, was used as the precursor over iron/nickel/manganese, iron/nickel/magnesium and iron/nickel/chromium trimetallic catalysts for the growth of MWCNTs. These trimetallic catalysts were prepared by sol‐gel method. MWCNTs produced were characterized by using Field Emission Scanning Electron Microscope (FE‐SEM) to indicate the production of nanotubes growth from palm DHSA. The density of the yield of MWCNTs produced differs with changes of the catalyst used during the nucleation process of MWCNTs. The crystallinity of MWCNTs was studied by X‐Ray Diffraction (XRD). Fourier Transform Infrared (FTIR) study was also been done for the prepared MWCNTs to check on the bonding occur in the produced MWCNTs.

In the current paper, we not only explain the fabrication and properties of an organic humidity sensitive field effect transistor using physical vapor deposition but also discuss the fabrication and properties of a photocapacitor made through spin‐coating technique. We also describe: (i) conduction mechanisms in organic semiconductors as hopping, band and/or tunneling one, and (ii) the possible ways to increase the mobility of charge carriers.

Nanocrystalline anatase and amorphous Titanium Dioxide (TiO2) thin film have been prepared using sol‐gel method and deposited by spin coater technique. The influence of annealing temperature on the structural, surface morphology and electrical properties of the thin film is characterized by Scanning Electron Microscopy (SEM) and I‐V measurement. The result indicates that nanocrystalline anatase phase can be obtained at annealing temperature of 300 °C or above. Titanium dioxide thin films were deposited on silicon substrates. Annealing temperature at T = As deposited, 100 °C, 300 °C and 500 °C have been observed. As deposited substrates is also observed. The result indicated electrical properties of titanium dioxide thin films were changed with annealing temperatures. As the annealing temperature rises, the resistivity will be decreased. The SEM investigation showed that grain size of titanium oxide increased with higher annealing temperature. Furthermore, the SEM result indicated lattice matching between titanium dioxide and substrate is important to produce good quality titanium dioxide thin film after annealing process. The results suggest that surface porosity, electrical properties and surface morphology of titanium dioxide could be affected by changing annealing temperatures for electronic devices application.

Vertical MOSFET has been introduced in the last few decades. As planar devices become smaller and smaller, vertical MOS transistor is one of the solutions for surpassing the short channel effects and pattern transfer. Thus, it is a promising approach to achieve channel lengths between 100 nm and 25 nm. In this work, we simulate sub‐100 nm single channel length vertical silicon MOSFET. The simulations are done with using ATHENA, DEVEDIT and ATLAS from SILVACO International. Input and output electrical characteristics of the vertical MOS transistors are investigated. The short channel effects of the vertical MOSFETs are explored. Due to the structure is not symmetry, source at top and bottom is also considered. The results also compared with experimental results from other researcher.

The density functional theory is used to make models of clusters of atoms of arsenic and selenium. We are able to determine the bond lengths and angles for which the energy of the Schroedinger equation is minimum. The vibrational spectra of the optimized clusters are computed by using several different wave functions. It is found that the double zeta wave functions work the best. For the optimized clusters, we calculated the vibrational frequencies in each case by calculating the gradients of the first principles potential. We compare the calculated values with those measured experimentally from the Raman spectra of As‐Se glass. The calculations have been done for many clusters, for example, (i) AsSe (diatomic), (ii) As2Se (linear), (iii) As2Se (triangular), (iv) As3Se (triangular), (v) As4Se (square), (vi) AsSe3 (triangular), etc. From this study we identify that linear As–Se–As for which the calculated frequency is 27.6 cm−1 is in agreement with the experimental data.

Aluminum doped zinc oxide thin films were prepared through sol gel and spin coating technique from zinc acetate dihydrate and aluminum nitrate nanohydrate in alcoholic solution. The electrical properties and surface morphology study are investigated for the thin films annealed at 350∼500 °C. Zinc oxide thin films deposited on glass and silicon substrates were characterized using electron microscopy (SEM) and current‐voltage (I‐V) measurement scanning for surface morphology and electrical properties study respectively. The SEM investigation shows that zinc oxide thin films are denser at higher annealing temperature. The result indicates electrical properties of aluminum doped zinc oxide thin films are improved with annealing temperatures. The resistivity of aluminum doped zinc oxide thin films are decreased with annealing temperature up to 500 °C.

Measurements of low frequency Raman scattering and low temperature specific heat between 2 and 20 K have been performed in two glassy, heterocyclic polymer networks. The effective network densities of heterocyclic polymer networks are varied by changing the ratio of bi- and mono-functional isocyanate monomers, leaving the overall chemical structure essentially unchanged. A boson peak at similar to 20 cm(-1) characterizes the Raman spectra at room temperature of both samples. Below 10 K, the specific heats deviate from a cubic temperature dependence, as predicted by the Debye theory, and reveal an excess specific heat, having the shape of a well-defined peak in a C(p)/T(3) plot with a maximum at similar to 5 K. The increase in effective network density is accompanied by a slight decrease in excess specific heat. These observations have been explained in terms of additional low-energy vibrations associated with the monomers building the polymer networks.

The Cengal wood samples which are obtained from Tenaga National Berhad (TNB), is a raw material for heavy construction industry. The compression test is carried out by using an Instron Machine Series‐IX at different temperatures for the purpose of determining and understanding the mechanical properties of Cengal wood under fiber saturated point and as dried samples. Analysis is made from the results in the form of Young's modulus, E plotted against the temperature. From the test, the Cengal wood does not show a glass transition or softening when dried up to 140 °C because there is no significant decrease in the value of E during heating. For fiber saturated point, the glass transition temperature occurs at 40 °C when the E value is about 190 MPa while the second rapid drop occurs at 60 °C (155 MPa), which is due to the softening temperature of lignin. After the softening point, the wood becomes too soft and undergoes the process of decomposition due to small value of E.

The effects of immersion time and quantity of Erbium plated on Nanostructured Silicon (NSi) have been studied. Nanostructured Silicon was prepared by electrochemical method with an electrolyte composed of Hydrofluoric acid and Ethanol. The Erbium plating process was carried out by immersion technique with electrolyte composed of ErCl3 and Ethanol. The photoluminescence (PL) effect on NSi samples have been studied and shows a PL intensity is improves at certain immersion time and the PL peak shifts to the blue luminescence. The presence of Erbium conformed by X‐ray Photoelectron Spectroscopy (XPS). Fourier Transform Infrared Spectroscopy (FTIR) was also performed to study the chemical functional group changes after the plating process. The possible mechanism of the effects will be discussed in this paper.

The tRNA molecule takes suitable amino acids to the ribosome for the formation of peptide bonds. In starting the peptide chain, the first amino acid taken to the ribosome is methionine. We have carried out calculations on the methionine‐tRNA and alanine‐tRNA complexes using mixed quantum mechanics ab‐initio and molecular mechanics method. The total energies and dipole moments have also been calculated. The amino acids chosen for this study, alanine and methionine have almost the same hydropath index. It is important to understand the physical properties and the environmental conditions in which the dipeptides cause the tRNA to attach to a wrong amino acid. One of the properties studied is the dielectric environment in which the bonding occurs.

The project is carried out using a small Mather type plasma focus device powered by a 15 kV, 30 μF capacitor. The filling gas used is argon. The ion beam generated is investigated by both time resolved and time integrated methods. Investigation on the dynamic of the current sheath is also carried out in order to obtain an optimum condition for ion beam production. The angular distribution of the ion emission is measured at positions of 0° (end‐on), 45° and 90° (side‐on) by using CR‐39 nuclear track detectors. The divergence of the ion beam is also determined using these detectors. A biased ion collector is used for time resolved measurement of the ion beam. Time of flight technique is employed for the determination of the ion beam energy. Average ion beam energy obtained is about 180 keV. The ion beam produced can be used for applications such as material surface modification and ion implantation.

Oxygen sensing properties of Er123 ceramic material utilizing hot‐spot phenomenon have been investigated. Bulk Er123 ceramic with relative density of 72 % was synthesized using solid‐state method and single‐phase structure of the material was confirmed by X‐ray diffraction. The Er123 sensor was fabricated by cutting the bulk sample into a rectangular rod shape. I‐V characterizations of the sensor before and after appearance of the hot spot were conducted in a chamber with controlled flow rate and partial pressure of oxygen and nitrogen gases. After appearance of the hot spot, the output current strongly depended on oxygen partial pressure (pO2) at a particular selected voltage. The sensor showed good sensing properties with minimum required electric field of about 1.7 V/cm for 0.025% to 100% pO2. The sensor showed very good reproducibility and stability of output current. The oxygen sensing properties are explained in terms of absorption of oxygen gas by the hot spot before dissociating into oxide ions an...

Polonium is the only element with a simple cubic (sc) crystal structure. Atoms in solid polonium sit at the corners of a simple cubic unit cell and no where else. Polonium has a valence electron configuration 6s26p4 (Z = 84). The low temperature α‐phase transforms into the rhombohedral (trigonal) β structure at ∼348 K. The sc α‐Po unit cell constant is a = 3.345 A. The beta form of polonium (β‐Po) has the lattice parameters, aR = 3.359 A and a rhombohedral angle 98°13′. We have performed an ab initio electronic structure calculation by using the density functional theory. We have performed the calculation with and without spin‐orbit (SO) coupling by using both the LDA and the GGA for the exchange‐correlations. The k‐points in a simple cubic BZ are determined by R (0.5, 0.5, 0.5), Γ (0, 0, 0), X (0.5, 0, 0), M (0.5, 0.5, 0) and Γ (0, 0, 0). Other directions of k‐points are Γ (0, 0, 0), X (0.5, 0, 0), R (0.5, 0.5, 0.5) and Γ (0, 0, 0). The SO splittings of p states at the Γ point in the GGA+SO scheme for α‐...

Photoluminescence and morphology studies of Zinc Oxide (ZnO) thin films prepared by using Thermal Chemical Vapor Deposition (Thermal‐CVD) were investigated. The ZnO compound was synthesized from zinc acetate dehydrate which act as a starting material to form the ZnO thin films. It was deposited on silicon with low deposition temperature ranging from 400–600 °C with Au as a catalyst assisted. Surface morphology of the samples was examined by Scanning Electron Microscope and photoluminescence properties were studied using Photoluminescence Spectrometer. The surface morphologies of the ZnO nano‐flower structure was obviously obtained at deposition temperature of 400 °C. The individual nano‐rods diameter of nano‐flower is about 100–350 nm, but the end of nano‐rods are very sharp which is the size is less than 50 nm. Possible growth mechanism of ZnO nano‐flower also discussed. Room temperature PL spectra from the ZnO nano‐flower revealed a strong UV emission and broad green emission. This result is very useful...

lead sulfide nanostructured thin film was prepared from colloidal lead sulfide nanoparticles with natural deposition technique. The size of PbS nanoparticles has been determined in the base of optical absorption spectrum. The influence of preparation method on the film surface morphology was studied by atomic force microscopy, and x‐ray diffraction. Experimental results have shown that the thin film uniformity has been improved when the number of deposited layer increased. Double layered PbS nanothin film has a self assembly morphology and can be used for surface plasmon applications.

In the present study, five systems of samples have been prepared by the solution casting technique. Polymethylmethacrylate (PMMA) is used as a based polymer. Ethylene carbonate (EC) and propylene carbonate (PC) as plasticizers. The salt that was selected for this study is lithium triflate (LiCF3SO3). The pure PMMA sample is taken as a reference. The five systems are the (PMMA–EC) system, the (PMMA–PC) system, the (PMMA‐LiCF3SO3) system, the ([PMMA‐EC]‐LiCF3SO3) system and the ([PMMA–PC]‐LiCF3SO3) system. The conductivity for each system is characterized using impedance spectroscopy. The conductivity of the pure PMMA, the (PMMA–EC) system and the (PMMA–PC) system at room temperature is 2.37×10−9 Scm−1, 3.63×10−8 Scm−1 and 4.18×10−8 Scm−1 respectively. On addition of salt in the (PMMA–LiCF3SO3) system, the conductivity is increased by two orders of magnitude. The conductivity for the ([PMMA–EC]‐LiCF3SO3) system and the ([PMMA–PC]‐LiCF3SO3) system is 3.54×10−5 Scm−1 and 2.06×10−5 Scm−1 respectively. The cond...

Aluminium and zinc target were co—sputtered on silicon (111) substrates using DC magnetron sputtering in the pure argon atmosphere. These films were then underwent the thermal annealing in different ratios of nitrogen and oxygen for 1 hour to form thin oxide films. P—type conduction in ZnO thin films have been realized by the Al—N codoping method, whereby the lowest resistivity of 3.41×10−3 Ω⋅cm and the highest carrier concentration of 1.54×1022 cm−3 was achieved for sample prepared at annealed temperature of 300 °C.

In this work the technique of laser‐induced breakdown spectroscopy (LIBS) has been used for the elemental analysis of cigarettes. For this purpose emission spectra have been measured of eleven different kinds of cigarette brands sold and/or produced in Pakistan. Analysis of the spectral peaks observed shows that Na, Mg, Al, K, Ca, Cr, Fe, Sr and Ba are contained in all brands. Exhibiting the LIBS results, the powerful potential of this method for the identification of the elemental content of cigarettes is demonstrated.

The codoped ZnO thin film were deposited by DC magnetron sputtering on silicon (111) followed by annealing treatment at 200 °C to 600 °C for 1 hour in nitrogen and oxygen gas mixture. P—type conduction of Al—N codoped ZnO thin films were obtained at 300 °C with the lowest resistivity of 3.412×10−3 Ω⋅cm and highest carrier concentration of 1.54×1022 cm−3. Structural investigation was carried out by atomic force microscope (AFM) and X—ray diffraction (XRD). Results showed that heat treatment had influenced the structure of the films.

This paper presents the influence of polysilicon depletion effect (PDE) on the potential drop across polysilicon gate. The effect of the gate doping and oxide thickness variations on the PDE has been investigated using MINIMOS 6.1 respectively. These parameter variations have been shown to be the factors that contribute to the polysilicon‐gate depletion effect that lead to the increase of the potential drop and degradation in device performance. Besides that, polysilicon depletion effect can be improved by reducing the oxide thickness (tox) and gate doping concentration (Np).

Multi‐wall carbon nanotubes (MWCNTs) were synthesized by thermal chemical vapor deposition (CVD) and were intercalated with iodine at several different temperatures. Iodine doping was achieved by immersing the nanotubes in molten iodine. The sample produced was characterized by means of infrared IR as a point to the presence of covalent C‐I bonds in the sample with retention of the sp2‐hybridizated carbon atoms. For all samples doped at different temperatures, the C‐I bonding happen to occur based on IR spectra which was indicated by peaks around 600–650 cm−1. X‐ray diffraction (XRD) characterization was used to study on the crystallinity of the undoped and iodine‐doped MWCNTs. It was shown that, iodine‐doping of the MWCNTs gives significant changes in the XRD spectra compared to the undoped MWCNTs. With various doping temperature, the XRD spectra shows the different crystallinity.

Superconducting fluctuation behavior has been studied in sintered polycrystalline samples of Yb‐substituted Tl0.5Pb0.5Sr2−xYbxCaCu2O7−δ (x = 0.1–0.4) by electrical resistivity measurements. Data of Δσ was obtained from linear fitting of the normal state resistivity in a suitable temperature region. Analysis of excess conductivity behavior based on Aslamazov‐Larkin (AL) theory revealed transition from 2‐D to 3‐D behavior of the superconducting fluctuation in the mean field region for all samples. This study also suggests that there is a close correlation between the amounts of Yb substitution and the behavior of AL constant (A) both for 2D and 3D fluctuations.

P‐N junction is a basic building block for many important electron devices from as simple as a solar cell to very complicated integrated circuit. In this work, spin‐on dopant (SOD) was used as the diffusion source in order to create p‐n junction. SOD was prepared by using sol gel method. The spin‐on dopant solution ingredients contain tetraethylorthosilicate (TEOS), isopropanol (IPA), distilled water (H2O), acetone and phosphoric acid (H3PO4). The coated silicon wafers were put inside the conventional furnace for predepostion and drive in oxidation. Effect caused by varying the molarity of the acid were observed and studied using Hall Effect measurement by comparing their differences in sheet resistance, mobility, resistivity as well as sheet and bulk concentaration.

The photoflash technique has been widely used for measuring thermal diffusivity of various types of materials. In this report thermal diffusivity of Zn‐Al layered double hydroxide synthesized at different ratios of Zn to Al composition is presented. The samples were prepared using Zn(NO3)2 and Al(NO3)3 solutions at pH of 10 by drop wise addition of NaOH solution with vigorous stirring under nitrogen atmosphere. Different compositions of Zn to Al molar ratios were obtained by changing the molar ratio of Zn(NO3)2 to Al(NO3)3. The slurry formed was kept at 70 °C in an oil bath shaker for 18 h, filtered, washed and dried in an oven for 18 h at 70 °C. A simple photo flash and polyvinlidene diflouride (PVDF) film was used as light source and thermal wave detector, respectively. Thermal diffusivity of Zn‐Al layered double hydroxide measure at room temperature was found increase with different compositions for Zn‐Al ratio of 3–5.

This paper presents the investigation carried out to study the formation of silicon nitride and silicon carbide compound from the reaction of silica sand powders with carbon in nitrogen with 5% hydrogen atmosphere at temperatures between 1350 °C to 1550 °C. The effect of mechanical milled silica sand and different temperature during carbothermal reduction process was determined. The morphology of the synthesis products was characterized using scanning electron microscopy and its composition was determined by elemental and X‐ray phase analysis. The formation of silicon nitride compound was facilitated by using silica sand with distorted structure by mechanical milling method. Further increased on temperature will lead to the formation of silicon carbide compound.

In this study, the plasma characteristics and GaN etch properties of inductively coupled Cl2/Ar plasmas were investigated. It has shown that the results of a study of inductively coupled plasma (ICP) etching of gallium nitride by using Cl2/Ar is possible to meet the requirement (anisotropy, high etch rate and high selectivity), simultaneously. We have investigated the etching rate dependency on the percentage of Argon in the gas mixture, the total pressure and DC voltage. We found that using a gas mixture with 20 sccm of Ar, the optimum etch rate of GaN was achieved. The etch rate were found to increase with voltage, attaining a maximum rate 2500 A/min at −557 V. The addition of an inert gas, Ar is found to barely affect the etch rate. Surface morphology of the etched samples was verified by scanning electron microscopy and atomic force microscopy. It was found that the etched surface was anisotropic and the smoothness of the etched surface is comparable to that of polished wafer.

In this work, the ion conducting films of polyacrylonitrile (PAN) containing plasticizer and dopant salts were prepared by the solution casting technique. The salts selected for this study are lithium triflate (LiCF3SO3) and sodium triflate (NaCF3SO3). The ionic conductivity measurements were carried out using impedance spectroscopy. The room temperature conductivity for pure polyacrylonitrile film is 1.51×10−11 S cm−1. The room temperature conductivity for the highest conducting film in the PAN‐LiCF3SO3 system and the PAN‐NaCF3SO3 system is 3.04×10−4 and 7.13×10−4 S cm−1, respectively. The conductivity‐temperature studies were performed in the temperature range between 303 K and 373 K. The variation of the conductivity with temperature is obeys the Arrhenius rule. The increase and decrease in the number of ions can be implied from the plots of dielectric constant, er‐frequency and dielectric loss, ei‐frequency.

This paper presents a detailed analysis of the fully and partially depleted silicon‐on‐insulator (SOI) n‐MOSFET for radio frequency (RF) applications. The analysis focused on the dependence of off‐state leakage current on temperature, oxide thickness, silicon film thickness, channel length, and buried oxide insulator of SOI n‐MOSFET respectively. The effect of varying each of this device's parameters on off‐state leakage current of SOI n‐MOSFET was investigated by using MINIMOS 6.1. The simulation results proved that decreasing of the buried oxide thickness and temperature lead to the reduction of the leakage current of the device.

The uptake of naturally occurring thorium, radium and potassium by sawi (Japanese Mustard) from disused tin mining was studied. Both soil and sawi sample were collected from a vegetable farm located 15 km from Kuala Lumpur, Malaysia where the farm has been operating for 22 years on a disused tin mining. By using a gamma spectroscopy system, the transfers of radionuclides from soil to plants were investigated. The highest values of radionuclides in the soil was K-40 which is 52.8 Bq kg{sup -1} and the lowest was Ra-226 which is 6.51 Bq kg{sup -1}. The activity of Th-232 is 18.5 Bq kg{sup -1}. The activity of radionuclides in the sawi sample shows higher values as compared to the soil sample. The highest values of radionuclides in the sawi were K-40 which is 446 Bq kg{sup -1} and the lowest was Ra-226 which is 17.5 Bq kg{sup -1}. The activity of Th-232 is 65.2 Bq kg{sup -1}. The concentration of radionuclides in soils and plants can be used for the determination of soil-to-plant transfer factors. The soil to plant transfer factors (TF) were calculated and observed to be 2.68 for radium-226, 3.52 for thorium-232 and the highest which is 3.97 formore » potassium-40.« less

This research was designed to form better dielectric composite material using one steady state dielectric with a good dielectric material. Distinct dielectric composite was successfully produced using locally sourced kaolinite clay. The samples were made using kaolinite as the base matrix and Strontium Titanate (ST) added in varying ratios. Strontium Titanate were synthesized via solid‐state reaction using Strontium Carbonate and rutile Titanium (IV) Oxide with sintering at 1300 °C. Local white kaolinite was used to fuse the barium titanate material in varying weight ratios. The powders were dry‐mixed and made into pellets for calcination at 1000 °C. The dielectric measurements were carried out using the HP 4291B Impedance Analyzer dielectric setup. Three samples were prepared, namely 10%ST, 20%ST and 30%ST. The dielectric measurements were carried out at room temperature. Microwave region measurements showed steady state and linear dielectric relaxation ranging from 7 in the control sample and dropping d...

Properties of the influence on the zeolite as the support towards the starting carbon materials by using thermal chemical vapor deposition (Thermal‐CVD) to produced carbon nanotubes (CNTs) are investigated. The CNTs derived from camphor oil (C10H16O), a botanical hydrocarbon, has been found to be a promising precursor of carbon nanotubes (CNTs). Multi‐wall CNTs have been grown from simple pyrolysis of camphor oil in the temperature 650 °C in argon atmosphere at normal pressure using zeolite as a supported on Fe/Ni/Mn catalyst. On the other hand, multi‐wall nanotubes of uniform diameter (∼20–30 nm) could be produced with a yield as high as 90%. Structural characterizations have been done by FESEM, and FTIR analyses. Good crystallinity, high purity, and absence of amorphous carbon and metallic particles are the essential features of camphor oil‐grown nanotubes; which indirectly may be cost effective. The major parameters are also evaluated in order to obtain high‐yield and high‐quality CNTs.

The characteristics of a defect counting tool, COMNET< based on scattering light measurement, is presented. This prototype supports the development of defect-free EUV blanks. Thanks to new improvements, it becomes possible to detect PSL particles having a diameter as low as 100 nm, with a video CCD camera, on silicon substrates or on EUV blanks. To reach this sensitivity, one of the enhancements consists in a laser irradiation close to 65°. The present configuration and the use of a CCD camera, with a variable exposure time, should lead to the detection of 80 nm PSL particles deposited on silicon substrate. This extrapolation is based on experimental results and on a simple model. To detect 100 nm particle and smaller particles, it is essential to reduce the level of stray light and to increase the signal to noise ratio. In our application, the stray light essentially comes from three sources: the noise induced by the roughness of the sample, the Rayleigh scattering of the atmosphere, and the stray light in the room. The restrictions induced by these phenomena are described in some detail. All the improvements are not only available for the characterization of silicon substrates but also for transparent blank substrates and for EUV mask blanks. The additional noise induced by the tranparent substrate is analyzed. The defects, whatever the compoent sizes and the component shapes can be detected. A cross characterization achieved with a commercial tool on silicon substate is reported. Counting measurements performed on EUV blanks are shown. Furthermore, a more explicit definition of added defects is proposed.

The acoustic absorption in amorphous silica was measured between 1 K and 20 K and at frequencies between 15 and 65 MHz. It was shown that in the range (3÷5) K there exists an absorption peak whose position is temperature dependent, thus indicating a thermally activated relaxation process. The experimental results were discussed in terms of recent theories based on the Anderson model. The absorption peak observed represents a new feature that cannot be fitted into the current theories. It was suggested that a more refined explanation could be found in terms of stochastic resonance, whose existence has been postulated elsewhere in order to describe the behaviour of the main absorption peak observed at higher temperatures.

In this paper, we present the study of the structural, optical and electrical of n‐type GaN grown on silicon (111) by RF plasma‐assisted molecular beam epitaxy (RF‐MBE). X‐ray diffraction (XRD) measurement reveals that the GaN was epitaxially grown on silicon. For the photoluminescence (PL) measurement, a sharp and intense peak at 364.5 nm indicates that the sample is of high optical quality. Hall effect measurement shows that the film has a carrier concentration of 3.28×1019 cm−3. The surface of the n‐type GaN was smooth and no any cracks and pits.