The Features of Photoionization Absorption in the Ultrasopt X-Ray Region

Abstract

The following results of the experimental and theoretical investigations of the spectral behavior of the photoionization cross sections in the ultrasoft X-ray region are discussed : 1. The notable depature from hydrogen-like behaviour of the atomic photoionization cross sections of the inert gases Ar, Kr and Xe ; 2. Similarity of the gross features of absorption spectra both gases and solids ; 3. Spectral behavior of absorption coefficients of Au and Bi, rare-earth metals, transition metals from Zr to Pd, and from Ti to Ni and from Ta to Au

Resonant photoemission of rare earth doped GaN thin films

“…The weighted oscillator strength, gf, relates directly to the electric dipole transition probability and, hence, line intensity. Theoretical interpretations of resonant photoemission in lanthanide metals at the 4d absorption threshold via gf calculations have been reported [45] and have been shown to agree well with experimental results [46]. The resonance peak, at roughly 147.5 eV for the GaN:Gd Fano line profile in Figure 4, illustrates reasonable agreement with the Gd gf calculations of Sugar [45], which indicated a strong absorption peak centered at 149.0 eV.…”

Study of the Excitation of 4d Electrons in Rare‐Earth Metals by Inelastic Scattering of a High Energy Electron Beam

“…The 4d-shell photo-absorption spectra of the trivalent rare earths [6,7] show a prominent peak about 10 to 15 eV above threshold, and numerous weak lines in the vicinity of the threshold. It must be emphasized that a typical intensity ratio between this resonance maximum and the weak discrete lines is about 100, and that the main peak appears to be composed of several peaks which are not completely resolved.…”

Time-resolved luminescence of LaBr3-Ce scintillation crystals upon selective UV-VUV-XUV excitation

“…The broad deep minimum at 118 eV in the PL excitation spectrum correlates with the absorption spectrum of the lantha num film [10]: the spectra are completely antibatic. The absorption of lanthanides in this energy range is considered a manifestation of giant resonance [11]. In this range of fundamental absorption, the absorption coefficient is extremely high (~10 radiative recombination of charge carriers on the Ce 3+ centers and the nonradiative recombination on the surface accounts for the structure of the PL exci tation spectrum.…”