Advantages and Limitations of ERDA

Using ERD one detects particles that are emitted from the sample surface. If the atomic identity of the particle is known, then the ERDA has the following advantages compared to RBS  

The depth dependent composition of the sample can be determined which is not possible with RBS technique. 

The scattering probabilities are much larger with heavier projectiles. 

Light elements become detectable because the scattering cross-section depends only very slightly on the atomic number of the target atom, whereas it depends quadraticaUy on the atomic number in the case of RBS. 

Since the energy resolution of silicon surface barrier detectors is bad for heavier ions, more complicated methods such as time of flight measurements or magnetic spectrometers are required. 

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