Advances in X-ray Analysis · 1979 · 37 citations · 11 references
X-ray CrystallographyHalf WidthScale FactorEngineeringMicroscopyElectron DiffractionChemistryIon ProcessIon EmissionCrystal FormationBiophysicsMaterials ScienceCrystalline DefectsPhysicsCrystal MaterialDiffractionPowder Diffraction ProfilesPhysical ChemistryAnanalytical Express IonCrystallographyDiffraction AngleNatural SciencesSpectroscopyMaterials CharacterizationApplied PhysicsX-ray DiffractionLine Broadening FactorsIon Structure
Abstract Powder diffraction profiles of well crystallized compounds can be fitted to distributions of the type I θ =I ° (1 + k 2 x 2 ) -n where k is a scale factor related to the half width of the profile. The value of n varies with the diffraction angle, 2θ, and is generally different for the low-angle and high-angle sides of the same profile. Limiting values of n for a specific Guinier camera-micro-densitometer combination are 1.2 ≤ n ≤ 2.3. Similar values are obtained for diffracto meter profiles after Ktt2 stripping. Line broadening due to departure from perfect crystallinity in the specimen affects the value of n a swell as that of k. The above observations are interpreted interms of the convolution of a Gaussian with a Lorentzian distribution, the exponent n of the convolute being dependent upon the relative half widths of these two functions, expressed as the ratio b L /b G .
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