【半导体培训资料】presentation3.pptx

XRD software for identifying crystalline structure: PowderCell 2.4, Crystallographica Search-match: X-Ray diffractometry2X-ray radiation was firstly discovered by Wilhelm Conrad R?ntgen in 1895 and won the noble prize in 1901.X-ray radiation is an electromagnetic wave, which lies in the range of the electromagnetic spectrum between ultraviolet radiation and gamma radiation, and corresponds to wavelengths from 10-2 to 102 ? (from 10-12 to 10-8 m) X-Ray diffractometryX-ray diffraction (XRD) analysis is the one of diffraction methods for studying the structure of material. The basis of this method relies on the phenomenon of x-ray diffraction by three-dimensional crystal lattice.This method was developed by Debye and Scherrer. The method allows to determine the atomic structure of material including the space group of the unit cell, its size and shape as well as the symmetry group of the crystal.3 X-ray diffractometer4X-Ray tubeSoller slitEquatorial slitanti-scatter slitreceiving slitSoller slitDetector slitDetectorSecondary monochromatorSchematic diagram of the Bragg-Brentano diffractometer X-Ray analysisThe most common type of diffraction studies are the phase identification (1) and the quantitative analysis of phase composition (2) in the sample.Using special databases (PDF2; PDF4)Using special software (PowderCell 2.4 or other) of by yourself5 XRD pattern6Intensity1st phase;2nd phaseAmorphous phase2θ PowderCell 2.4-This program uses the PDF4 database;Allows to determine both phase content and content of the main phases in percentages;- Allows to find Coherent scattering regions and microstress level in the material lattice.7 PowderCell 2.48 Folder Cell (PDF 4 base)9 Folder X_Y – here you should keep you XRD files10 PowderCell 2.4 Interface11 Crystallographica Search-Match-This program uses the PDF2 database;Allows to determine only phase content but the database is higher;- Allows to compare different XRD patterns and make the picture and convert it int