Photoabsorption Coefficient of Alloys of AI with Transition Metals V, Fe, Ni and with Cu and Pr from 30 to 150 eV Photon Energy

Abstract

Abstract The absorption coefficient of VAI 3 , FeAI, NiAI, NiAl 2 , CuAI 2 , PrAl 2 , and of disordered V–AI(16 at% AI, 28%, 41%) and FeAI (11%) alloys has been measured in the region of the M 2, 3 absorption of the transition metals and the Labsorption of AI. The strong changes of the AI spectrum in the region of the 100 eV maximum upon alloying are explained as another evidence of the EXAFS (extended X‐ray absorption fine structure) nature of these structures. The broad, prominent absorption peaks from the 3p excitations in V and Fe and from the 4d excitations in Pr are influenced only little on allyoing and thus appear to be of atomic origin. The fine structure at the onset of the Pr 4d transitions is identical in the metal and the alloy but differs from that of Pr oxide. The only M 2, 3 edge which is detectably shifted is that of Ni (up to 2.1 eV), whereas the onset of the AI L 2, 3 edge is shifted in all the alloys (up to 1.1 eV). The shifts are interpreted in accordance with X‐ray fluorescence and nuclear resonance measurements as changes of the density of states in the valence band of the alloys.