Study of M_4,5-Level Soft X-Ray Appearance Potential Spectra of Selected Rare Earths

Abstract

Soft x-ray appearance potential spectroscopy (SXAPS) is recognized as an important technique for the study of core electron binding energies and the density of unoccupied states above the Fermi level.¹ The purpose of this paper is to show a comparative study of the M4,5-level SXAPS spectra of the rare earth metals Ce⁵⁸, Pr⁵⁹, Tb⁶⁵, Dy⁶⁶, Ho⁶⁷, Er⁶⁸, Tm⁶⁹, and Yb⁷⁰. We have attempted to compare the spectra in terms of total x-ray fluorescence, width and height of positive peaks and the fine structural features, and to correlate the findings with increasing Z. The spectrometer used for the measurements, has been described in detail elsewhere. In each case, the samples were high purity polycrystalline metal foils which were argon ion sputtered and annealed in an attempt to obtain a clean surface for examination.

Supported by grants from Robert A. Welch Foundation and East Texas State University.