Скачать презентацию Applications of X-rays to Geology Part V XRD Скачать презентацию Applications of X-rays to Geology Part V XRD

Part V_XRD.pptx

  • Количество слайдов: 7

Applications of X-rays to Geology Part V. XRD analysis. Applications of X-rays to Geology Part V. XRD analysis.

Part V. XRD analysis. • X-ray diffraction • X-ray crystallography Part V. XRD analysis. • X-ray diffraction • X-ray crystallography

X-ray Diffraction. . . Why “Phase” Matters 1. The atomic (chemical) composition is obtained X-ray Diffraction. . . Why “Phase” Matters 1. The atomic (chemical) composition is obtained from XRF 2. The same atoms may arrange in different geometries or crystal structures the resulting natural materials are called minerals or phases 3. The crystal structure determines the physical properties of a material. Therefore, minerals with the same/similar chemistry may differ in: • Hardness • Colour or spectral absorption of light • Durability or wear resistance • Solubility • Cleavability, grindability • many more. . . 4. Knowing the phases has immediate financial impact: • The economic value of a material • Costs of mining, transport, processability • Properties of a final product http: //www. bruker. com/fileadmin/user_upload/8 -PDF-Docs/X-ray. Diffraction_Elemental. Analysis/XRD/Webinars/Bruker_AXS_Industrial_Minerals_Webinar_Slides. pdf

What is X-ray Diffraction? The Mineral “Fingerprint” http: //www. bruker. com/fileadmin/user_upload/8 -PDF-Docs/X-ray. Diffraction_Elemental. Analysis/XRD/Webinars/Bruker_AXS_Industrial_Minerals_Webinar_Slides. What is X-ray Diffraction? The Mineral “Fingerprint” http: //www. bruker. com/fileadmin/user_upload/8 -PDF-Docs/X-ray. Diffraction_Elemental. Analysis/XRD/Webinars/Bruker_AXS_Industrial_Minerals_Webinar_Slides. pdf

What is X-ray Diffraction and How Does It Work? Bragg’s equation: λ = 2 What is X-ray Diffraction and How Does It Work? Bragg’s equation: λ = 2 d sin Θ • • • The x-ray wavelength is of the same order as the distances in the crystal lattice For each possible d-spacing (distance between parallel sets of planes with atoms in a crystal lattice), a peak is observed at a distinct angle 2Θ. The atoms and their positions in the unit cell determine the peak intensities. http: //www. bruker. com/fileadmin/user_upload/8 -PDF-Docs/X-ray. Diffraction_Elemental. Analysis/XRD/Webinars/Bruker_AXS_Industrial_Minerals_Webinar_Slides. pdf

Bragg’s law and minerals identification Bragg’s equation: λ = 2 d sin Θ Let Bragg’s law and minerals identification Bragg’s equation: λ = 2 d sin Θ Let λ is known value, then di-spacings for a crystal can be calculated from measured angles Θi:

Summary. Practical Uses • XRD is the most applied technique for routine mineral identification. Summary. Practical Uses • XRD is the most applied technique for routine mineral identification. Terra Portable XRD Easy Sample Preparation http: //www. olympus-ims. com/ru/xrf-xrd/mobile-benchtop-xrd/terra/ http: //www. csub. edu/~dbaron/Labs. html