Calibration of PIXE yields using binary thin films on Si

We describe the use of binary thin films on Si to calibrate the yields in proton-induced X-ray emission (PIXE) measurements. Besides of the element to be calibrated, the standards also contain a common reference element. The incorporation of a common reference element allows one to eliminate errors in the accumulated beam charge during the calibration of the PIXE set-up. The binary calibration standards allow us to determine the response function with an accuracy close to 1%. As an example, we will perform the calibration for Fe and Co, and we will determine the Co concentration in Fe_1−xCo_x thin films