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Yu-Lung 2 and 3 - Coggle Diagram
Yu-Lung 2 and 3
Wavelength dispersive X-rays (WDX)
Diffraction happens when:
\(\lambda = 2d \sin(\theta )\) is satisfied
Analysing crystal acts as a mirror
\(\theta \) is continuously changed, along with x-ray wavelength and positioning the detector, x-ray intensity is measured as function of wavelength
Compared to EDX:
:check:Better resolution
:check:More efficient at detecting light elements
:check:Higher signal to noise ratio (1000x higher)
:red_cross:Longer time required for analysis
Transission Electron Microscopy (TEM)
Used to measure the amount of elements
Chamical analysis at high spatial resolution
Uses electrons passed through a thin sample and recieved the other side, rather than reflected like SEM
Uses Electron Energy Loss Spectroscopy (EELS)
Measures the change in KE of electrons after interacting with the sample
Electron diffraction
Very small Bragg angle
Electron beam direction and diffracting plane are nearly parallel
Forms a diffraction pattern of spots:
Individual crystal can be rotated in double hilt holder
Can be used to determine crystal structure
As 2\(\theta\) is very small, it is essentially =R
Measure angle between diffraction spots to confirm indexing
Cross product of two vectors gives beam direction
SEM
Si-Li detector
Narrow spectrum peaks mean good resolution
How to read a spectrum
Ignore background noise
Clear separation of peaks
Position of peak = Element
Area under peak = Concentration
Integrate to find area under peak
Soft x-ray Emission Spectrometer (SXES)
Positives :check::
Excellent light element detection
Ideal for chemical shift analysis(battery research)
Good sensitivity
Energy range 50eV - 210eV
Extreme resolution 0.3eV
No moving parts
Can be either part of a system or stand alone
Easy to use mapping
