An EXAFS Study of Short-Range Structure of Amorphous Pd–Ti Alloys

Abstract

The atomic-scale structure of amorphous Ti_100−xPd_x (x=34, 37, 45 and 48) alloy films produced by RF sputtering has been studied using the EXAFS technique. EXAFS spectra at both Pd K-edge and Ti K-edge have been examined. The interatomic spacings between the nearest neighbors, r_Pd–Pd, r_Ti–Ti and r_Pd–Ti, have been evaluated and compared with those of crystalline films of Pd, Ti and their solid solutions. The magnitudes of these nearest-pair distances are consistent with those evaluated by X-ray diffraction of the same materials. It has been found that r_Pd–Ti is ∼10% smaller than the arithmetic mean of r_Pd–Pd and r_Ti–Ti. This constriction is attributable to covalent bonds formed between Pd and Ti atoms.