A XAFS Study on the Site Determination of Additives in the Ni3Al Intermetallic Compound

Occupied sites by dopants of Ag(0.1 at%), Pd(2at%) and Zr(0.4at%) in the Ni3Al intermetaillic compound are investigated by means of EXAFS analysis. It is found that Pd substitutes the Ni site and Zr substitutes the Al site. These results are consistent with tthose of channeling enhanced microanalysis. Ag is also determined to substitute in the Ni site by EXAFS and this result supports that Ag additive is γ-phase(disorder phase) former. The expansion of the nearest neighbor distance around Ag, Pd and Zr are 2%, 3% and 4% respectively