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X-ray Fluorescence

Introduction

X-ray fluorescence is a spectroscopic method that is commonly used for solids in which secondary X-ray emission is generated by excitation of a sample with X-rays. The X-rays eject inner-shell electrons. Outer-shell electrons take their place and emit photons in the process. The wavelength of the photons depends on the energy difference between the outer-shell and inner-shell electron orbitals. The amount of X-ray fluorescence is very sample dependent and quatitative analysis requires calibration with standards that are similar to the sample matrix.


Instrumentation

Solid samples are usually powdered and pressed into a wafer or fused in a borate glass. The sample is then placed in the sample chamber of an XRF spectrometer, and irradiated with a primary X-ray beam. The X-ray fluorescence is recorded with either an X-ray detector after wavelength dispersion or with an energy-dispersive detector.


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