X-ray fluorescence - Moseleys Law

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X-ray emission spectroscopy from 1913!!

 

Sharp peak spectrum, the wavelengths of the peaks are target element dependant - known as the "characteristic X-ray spectrum" of an element. First studied by Moseley in 1913 in Manchester (he worked for Rutherford) using

X-ray diffraction from crystals.

The most intense short-wavelength line (called Kα) was found, as a function of element, to have a frequency dependant on the Z of the element:

 

 

X-ray absorption is also element specific: 

 

absorption edges - sudden changes in absorption co-efficient at particular, element specific wavelengths

 

Both arise from electron inner shell transitions in atoms.

 

©  Peter Hammond  2004