Papers by Keyword: FWHM

Abstract: The aging of the precipitate product is a crucial stage in forming particles using the precipitation method. In this study, the aging time in atmospheric ambient was investigated for its impact on the formation and properties of zinc oxide particles. The zinc oxide particles were synthesized using an ultrasound-assisted precipitation method. The diffraction pattern confirmed the crystallinity and crystallite size of zinc oxide decreases with increasing aging time. The UV-Vis absorption spectrum analysis revealed that 24 hours of aging resulting zinc oxide with a bandgap close to that bulk zinc oxide band gap energy. The scanning electron microscope image showed an alteration of zinc oxide morphology from rod to flake-like particle as the aging time. The crystallinity, morphology, and optical properties of zinc oxide particles are significantly affected by aging time. The results suggested that aging time in the ultrasound-assisted precipitation method can be used to engineer the suitable properties of zinc oxide particles for its application.

Abstract: The production of a high-sensitivity surface Plasmon resonance (SPR) sensor depends on a few main factors, such as metal thin film types and thicknesses, light coupling techniques and acceptable EM wave polarization modes. This work is carried out to investigate the impact on the SPR characteristics of noble metal thicknesses, namely gold and silver, for optical sensor applications. To excite surface Plasmon polaritons (SPP), a Kretschmann prism coupling was used. The thicknesses of noble metal thin films were varied between t=30nm and 60nm. The characteristics of SPR peaks such as Q-factor and FWHM were studied in SPR signal analyses. In comparison with silver, Q-factor results showed an outstanding optical property of gold at t= 40 nm due to its high Q-factor values, which confirms its ability to produce excellent SPP quantities. In conclusion, gold noble metal at t= 40nm is capable of producing optimum SPR. In the development of the highly sensitive SPR sensor, this excellent criterion put gold as a spectacular candidate for optical sensor applications.

Abstract: The aim of this work is to study the influence of x-ray diffractometer scanning parameters on the integrated intensity and full-width at half maximum (FWHM) of copper powder x-ray diffraction peaks by using statistical analysis methods. X-ray diffraction (XRD) analysis of the copper powder was accomplished using step scan mode with step sizes of 0.03^o and 0.05^o 2q, and preset time changes from 0.1-3.5 s. Integrated intensity of an x-ray peak was calculated by the numerical method. FWHM was measured as the width of Pearson VII model of the x-ray peak at the half-maximum intensity. The statistical analysis methods including linear regression and statistical hypothesis test were used to analyze the correlation between the preset time and the error on integrated intensity calculation, and the FWHM of a peak on the XRD pattern. The results from statistical analysis show that increasing the preset time from 0.1 s to 3.5 s does not affect the FWHM of an x-ray peak, but it reduces the relative error in integrated intensity calculation. Moreover, using the preset time greater than 1 s will minimize the relative error in integrated intensity calculation of an x-ray peak. While step size did not affect both the relative error in integrated intensity calculation or FWHM, the smaller step size would provide more data points for better accurate model of an x-ray peak.

Abstract: Zircon samples from Ubon Ratchathani, Thailand; Rattanakiri, Cambodia and Dak Nong, Vietnam change their color from light brown and reddish-brown to blue color after thermal enhancement at 1000 ^๐C in reducing condition for 60 min. The high temperature is one of the factors for the zircon structure to recrystallize. The objective of this study is to describe the crystal structure of zircon samples before and after thermal enhancement. Zircon is a metamict mineral whose structure is destroyed by some trace elements. There are radioactive elements such as U and Th in the zircon structure. In this study, Raman spectroscopy was used to analyze the molecular vibration in zircon structure before and after thermal enhancement. As a result, the Raman spectra of zircon samples after thermal enhancement show the Raman shift at peak position of V₃(SiO₄) stretching around 1008cm^-1 to higher wavenumber concerning to the full width at half maximum (FWHM) values calculated by PyMCA software. The results could be summarized that the metamict zircon will be recrystallized to the crystalline zircon after thermal enhancement. The advantage of this study is about the identification of zircon before and after thermal enhancement.

Abstract: Aluminum nitride (AlN) film as a piezoelectric material has been used widely, particularly in vibration energy harvester due to its unique and enhanced properties such as high temperature resistance and compatibility with CMOS processes. In this work, AlN film with (002) preferred orientation was prepared on silicon wafers by pulse DC reactive magnetron sputtering (RMS), and the properties such as peak intensity, full width at half maximum (FWHM) and surface morphology were investigated by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The preferred orientation was found to be sensitive to deposition conditions such as gas flow rate, power, bottom electrodes materials and substrates temperature. The results shows that the intensity was 1.1×10⁵ counts, the FWHM was 1.9owhen the temperature was 260°C. The film was used to fabricate the vibrated energy harvester successful and the power density reached about 3000uW/cm³ at the vibration frequency under 1g acceleration.

Abstract: Aluminium alloys welded with arc welding and electron beam welding processes were investigated to analyse the local deformation behaviour under static loads. Therefore strain measurements were carried out. These investigations were combined with X-ray diffraction experiments which should provide information about the residual stress condition and additionally about load-induced changes of the hardening condition. Additionally diffraction experiments using synchrotron and neutron radiation where carried out to analyse the deformation behaviour of particular welds under varying static loads.

Abstract: Silver nanoparticles are synthesized using N,N dimethyl formamide (DMF) both as reductant as well as solvent. The reaction is performed in the presence and absence of surfactants at room temperature to know the effect of the same on the size and shape of the silver nanoparticles. In this regard, two different surfactants viz. polyvinylpyrolidone (PVP) and cetyl trimethyl ammonium bromide (CTAB) are used. The rate of the reaction and the formation kinetics is continuously monitored by UV-vis spectroscopy at regular time intervals. The corresponding change in plasmonic peaks and full width half maxima (FWHM) is studied in detail. The particle size is determined using Mie plot.

Abstract: BST thin films have been grown by Chemical Solution Deposition (CSD) method on the substrate of Pt/Si. The fabrication of BST doped by Fe have been successfully using spin coater with 4000 rpm during 30 second. Annealing process use the holding time at 3 hours, the heating rate at 5°C/min and temperature at 800°C. The ratio of Ba_0.8Sr_0.2TiO₃ molar and Fe variant dopant (0%, 1%, 3%, and 5%) were characterized by X-Ray Diffraction (XRD) and obtaining results that show the peak shift due to variations dope. The peak shifted to the right for each increment Fe dopant. Results of addition Fe dopant also cause a differences in the magnitude of Full Width at Half Maximum (FWHM) and lattice parameters on BST ferroelectric materials. Other characterize that has been done by Scanning Electron Microsopy (SEM), it is show the thickness of the material. The resulting lattice parameters with the General Structure Analysis System (GSAS) software analysis showed that a thin films of BST and BSTF have a tetragonal structure because it has a value of a=b≠c and α=β=γ=90⁰. Based on SEM characterization, the thickness of thin film is about 330 nm.

Abstract: In the present study, we have successfully grown Si-doped AlN developed by solution growth technique using Ga-Al melt as a solvent under nitrogen atmosphere at 1300 °C. Si doping was introduced to the Ga-Al melt by adding pure Si metal. To allow homoepitaxial growth during solution growth experiment, sapphire substrate were nitrided with precise control to produce hiqh quality single crystalline AlN films with low dislocation density. With the help of AlN film template from above methods, we have successfully grown Si-doped AlN single crystalline layer with a flat surface and almost free from cracks. The full width at half maximum (FWHM) of x-ray rocking curve values for (0002) and (10-12) diffraction from the Si-doped AlN film were 43,2 and 594 arcsec, respectively.