SOFT-X-RAY-EXCITED SOFT-X-RAY APPEARANCE-POTENTIAL SPECTRA OF SM AND SMB6 IN THE SM 3D ELECTRON-EXCITATION REGION

The resonant process previously proposed in electron-excited SM M4,5 emission spectra of Sm and SmB6 was confirmed by a study of soft-x-ray-excited soft-x-ray appearance-potential spectra (XXAPS). Two peaks were observed in the XXAPS at photon energies equal to energies of the prominent peaks in the Sm M4,5 absorption spectra. These peaks are attributed to the resonant process 3d(10)4f(n)<-- -->3d(9)4f(n+1), where n is the number of 4f electrons in the ground state. In addition to the resonant peak in the M5 spectral region, the resonant peak in the M4 spectral region, which was not separately observed from the diagram line M4N6 in electron-excited emission spectra, was clearly observed in XXAPS.