BOND-LENGTH DETERMINATION FOR TRANSITION ATOMS BY SHALLOW LEVEL EELFS

We report the complete analysis of extended energy loss fine structure (EELFS) above M(2,3) edges of Cu and Ni in terms of radial distributi on functions, single-shell oscillations, envelope and phase functions. M(2,3) spectra of Cu and Ni were measured and calculated in the curve d-wave approximation taking into account both 3p- and 3d-ionization pr ocesses. The excellent agreement of the experimental and theoretical d ata provides the evidence of the strong influence of 3d-ionization on the M(2,3) EELFS, eliminating previously reported significant errors i n the first-shell distance determination in shallow level EELFS spectr oscopy.