Analisis Struktur Kristal dan Struktur Lokal Menggunakan Data Wide Angle X-Ray Scattering (WAXS) dan X-Ray Absorption Spectroscopy (XAS) Sinkrotron

Muchlis, Khairanissa (2017) Analisis Struktur Kristal dan Struktur Lokal Menggunakan Data Wide Angle X-Ray Scattering (WAXS) dan X-Ray Absorption Spectroscopy (XAS) Sinkrotron. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pada penelitian ini telah dilakukan analisis struktur kristal dan struktur lokal dari data Wide Angle X-ray Scattering (WAXS) dan X-ray Absorption Scattering (XAS) yang diperoleh menggunakan radiasi sinkrotron pada SLRI (Syncrotron Light Research Institute), Thailand. Semua data WAXS dikonfirmasi dengan data difraksi sinar-X (XRD). Analisis yang dilakukan berbasis structure refinement menggunakan metode Rietveld dengan perangkat lunak Rietica. Fraksi komposisi fasa berada dalam rentang yang sama, dengan rata-rata ralat untuk XRD sebesar 2%, WAXS sebesar 4%. Parameter kisi hasil data XRD dan WAXS memiliki nilai ketidakpastian yang relatif sama yaitu XRD=0,035%, WAXS=0,038%, tetapi nilai utamanya berbeda cukup jauh yaitu 0,01-0,1. Analisis struktur lokal (local structure) dengan teknik X-ray Absorption Structure (XAS) menggunakan Si K-edge. Analisis kuantitatif struktur lokal dengan EXAFS menggunakan program ARTEMIS menghasilkan informasi jarak antar atom terdekat dengan atom absorber, dan nilai Debye-Waller factors (2). Fitting yang paling baik adalah data fasa tunggal yaitu sampel kuarsa dengan faktor-R (kualitas pencocokan) kurang dari 0,02. dengan jarak atom absorber Si ke atom tetangga terdekat pertama yaitu O (jarak Si-O1) sebesar 1,6 Å, 2=0,0026. Selanjutnya sampel kristobalit yang terdiri atas dua fasa memiliki nilai faktor-R sebesar 0,023, dan sampel forsterit dengan faktor-R sebesar 0,035. Analisis XANES dilakukan secara kualitatif karena analisis data XANES lebih kompleks dari pada analisis EXAFS. ================================================================================================================== In this research, the structure and local structure of some samples have been analyzed using Wide Angle X-ray Scattering (WAXS) dan X-ray Absorption Scattering (XAS) data. The data was obtained using synchrotron radiation at Synchrotron Light Research Institute (SLRI), Thailand. All of WAXS data was confirmed using X-ray Diffraction (XRD) data. The method of analysis based on structure refinement using Rietveld method with Rietica program. Both WAXS and XRD weight fraction are similar with average standard deviations of 4% and 2% respectively. Meanwhile the XRD and WAXS lattice parameters have similar standard deviations, i.e. 0,035% and 0,038%, but their absolute values are different by values between 0.01 and 0.1. Si K-edge was used for determining local structure using X-ray Absorption Structure (XAS) technique. Quantitative analysis were done using ARTEMIS program. The information of fitting results were the distance between absorber atom to the nearest neighbour atom, and Debye-Waller factors (2) value. The best fit is for quartz single phase sample which has R-Factor less than 0.02, with the distance of atom absorber Si to the first neighbour atom O (distance Si-O1) 1,6 Å, 2=0,0026. Next is a two-phase cristoballite sample with R-factor of 0.023 and a three-phase forsterite sample with R-factor of 0.035. XANES analysis is more complicated than EXAFS, therefore the XANES data is analyzed qualitatively.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Crystal structure, Local Structure, XRD, WAXS, EXAFS, XANES,struktur kristal, struktur lokal
Subjects: Q Science
Q Science > QC Physics
Divisions: Faculty of Mathematics and Science > Physics > (S2) Master Theses
Depositing User: KHAIRANISSA MUCHLIS
Date Deposited: 03 Apr 2017 04:13
Last Modified: 03 Apr 2017 04:13
URI: http://repository.its.ac.id/id/eprint/2462

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