Evolution of Cu–Lα fluorescence lineshape during aging of Cu–Al studied with direct excitation by undulator radiation

Abstract The high sensitivity obtained by direct excitation by undulator radiation allows the shape of the Cu–L αβ fluorescence spectrum to be measured accurately also at low Cu concentrations. We study the evolution of the L α lineshape of 0.5 and 1.5% Cu in Al following the thermal history of the sample. The Cu spectra in the precipitates are given and the formation of Guinier–Preston (GP1) zone of type 1 is studied for the first time with this approach. The results point out the importance of GP1 arrangement with platelets rich in Cu. The effect of selfabsorption on the L αβ spectra is also investigated.