4d-Shell Photoabsorption Spectra of Lanthanum- and Cerium-Halides

Abstract

The photoabsorption spectra of 4d electrons have been measured on LaF₈, LaCl₃, CeF₃, CeCl₈, and CeBr₃ as well as on metallic La and Ce. The spectra consist of two parts. One is the line structure near the threshold and the other is the broad and intense band (giant band) following the line structure. The observed features of the spectra concerning the line structure are independent of halogen and in agreement with existing atomic theoretical calculations. On the other hand, the profile of the giant band in La-halides is dependent on halogen. The ³D₁ line in La-halides is found to have an asymmetric line-shape. In the measurements by photographic method using synchrotron radiation, temperature dependence of the spectra is not detected.