Defect Detection in Fe-Cr Alloys with Positron Annihilation Doppler Broadening Spectroscopy
Positron annihilation Doppler broadening spectroscopy (DBS) has been used for the detection of structural defects in Fe-9wt%Cr (Fe-9Cr) alloy in the as-prepared and implanted states. Defects were created by He and H ion implantation with a kinetic energy of 250 keV. DBS is a non-destructive method and is a unique tool for the observation of open volume defects like vacancies and vacancy clusters in solids. A positron beam with variable positron energy was used for the measurement of defect depth profiles up to 1.5 µm. The obtained results provide qualitative and semi-quantitative information about radiation induced defects and their chemical environment. Although the collision damage from helium implantation was one order of magnitude higher than for the case of hydrogen, the changes in S and W parameters are much less significant, probably due to considerably lower mobility of helium in the implanted materials, which results in helium capture by the created open volume defects.
Jozef Krištiak, Jan Kuriplach and Pradeep K. Pujari
V. Sabelová et al., "Defect Detection in Fe-Cr Alloys with Positron Annihilation Doppler Broadening Spectroscopy", Materials Science Forum, Vol. 733, pp. 270-273, 2013