X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY OF INDIRECT EXCHANGE INTERACTION IN ORTHONIOBATE LANTHANOIDS LNNBO(4)

By the XPS method, orthoniobate lanthanoids LnNbO(4) (where Ln represe nts lanthanoids except Pm and Tm), representing a new number of ferroe lastics were studied in the range of electron binding energies from 0- 1350 eV. The decreasing of the relative shake up satellite intensity w ith the decreasing of the electron binding energy of various subshells of the lanthanum ion was confirmed. The dependence between the Nb as- electron line width and the number n of uncoupled Ln 4f(n) electrons w as discovered. It was supposed that such an affect arises as a result of indirect exchange interaction between the lanthanoid ion and the ni obium ion through oxygen. (C) 1998 Elsevier Science B.V.