4f STATE WITH THE 3d CORE HOLE OF La, Sm AND SmB₆

Abstract
The Sm M_4,5 emission and characteristic isochromat spectra of Sm metal and a mixed-valence compound SmB₆ and the La M_4,5 fluorescent emission spectrum of La metal were measured to obtain the information on the 4f state with the 3d core hole. In the case of Sm metal and SmB₆ it was found that an electron-beam energy larger than the energy of the resonant emission (1079 eV) and also the threshold of the 3d_5/2 leyel (1082.2 eV) is required for the generation of the resonant emission (3d^-1_5/24fⁿ⁺¹ → 3d¹⁰4fⁿ), where n is equal to 5 for the Sm³⁺ ion. The hole-induced shakedown process was observed in the M_4,5 fluorescent emission spectrum of La metal.