L-GAMMA(1) AND L-BETA(2,15) X-RAY-EMISSION LINES OF RARE-EARTH TRIFLUORIDES AND CEO2

X-ray emission spectra due to the rare-earth 4d --> 2p(1/2) (L gamma(1 )) and 4d --> 2p(3/2) (L beta(2,15)) electronic transitions in rare-ea rth compounds have been measured with x-ray excitation. The satellite structure due to the 4d-4f exchange interaction in the final state is observed in Ce compounds, as seen in other heavier rare-earth compound s. The intensity ratio of the satellite to the main band in the L gamm a(1) line is larger than that in the L beta(2,15) line, which is consp icuous in heavy rare-earth compounds. The experimental results are wel l explained by the theoretical calculation, where the multiplet coupli ngs and the dependence of the 4d core-hole decay rate on the multiplet terms are taken into account. It is found that the spectral shapes of CeF3 and CeO2 resemble each other as a result of the phase matching o f the wave functions between the intermediate and final states.