Chemical shifts of the K-absorption edge of Mn and the L,-absorption edges of rare earths (R = Gd, Tb, Dy, Ho, Er, Tm, and Lu) in RMn, intermetallic compounds are measured and the effective charges on the Mn and R ions are estimated. Extended X-ray absorption edge fine structures (EXAFS) associated with the absorption edges are investigated and R-Mn and Mn-Mn bond lengths in R-Mn, compounds are determined. The results are interpreted in the light of the available data on these intermetallic compounds. Es werden die chemischen Verschiebungen der K-Absorptionskante von Mn und der L,-Absorptionskanten Seltener-Erden (R = Gd, Tb, Dy, Ho, Er, Tm und Lu) in intermetallischen RMn,-Verbindungen gemessen und die effektive Ladung auf den Mn-und R-Ionen ermittelt. Die mit den Absorptionskanten assoziierten, ausgedehnten Feinstrukturen der Rontgenabsorptionskanten werden untersucht und die Liingen der R-Mn-und Mn-Mn-Bindungen ermittelt. Die Ergebnisse werden ausgewertet unter Heranziehung von verfiigbaren Daten fur diese intermetallischen Verbindungen.
IntroductionExtensive work has been carried out on magnetic, electronic, and transport properties of rare-earth intermetallics and alloys with transition elements [l]. Recently, we reported the results of X-ray spectroscopic studies on intermetallic compounds of rare earths with platinum and cobalt and these were correlated with the available data obtained from other techniques [2, 31. I n this communication we present the results on RMn, (R = Gd, Tb, Dy, Ho, Er, Tm, and Lu) compounds. We have measured the X-ray absorption edge shift both for Mn and R ions and estimated the effective charges on these ions. Further, extended X-ray absorption fine structures (EXAFS) associated with the absorption edges are investigated and these are used for estimating the R-Mn and Mn-Mn bond lengths in RMn, intermetallics.RMn, compounds crystallize with cubic Laves phase structure for R = Gd, Tb,