Extended X‐Ray Absorption Fine Structures and Chemical Shifts for the Heavy Rare‐Earth Oxides

Abstract

Abstract L 3 ‐absorption edges and the associated extended X‐ray absorption fine structures (EXAFS) for dysprosium, holmmm, thulium, ytterbium, and lutetium in pure oxide form are investigated using a 600 mm curved crystal spectrograph. A forbidden transition corresponding to an electron transition, 2p 3/2 ‐→ 4f (unoccupied), is detected for Dy 2 .,O 3 , Ho 2 0 3 , and Tm 2 O 3 with open 4f‐shell. Chemical shifts are measured and an attempt made to correlate these with the estimated effective charges on the ions indicates a new trend not reported by others. A prominent absorption peak, A (white line), is also recorded for the oxides. The reduced width of these white lines for oxides indicates the narrowing of the 5d band. The metal‐oxygen distances determined using EXAFS methods agree with the crystallographie data. Shapes of the EXAFS for oxides resemble with each other while they differ from those recorded for the corresponding metals.