An Analysis of the Mössbauer Spectral Hyperfine Parameters of RFe₁₁Ti and RFe₁₁TiH, Where R Is a Rare-earth Element


The Mössbauer spectra of CeFe11Ti and CeFe11TiH obtained between 4.2 and 295 K are analysed in terms of the model used to analyse the spectra of the RFe11Ti and RFe11TiH compounds, where R is Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Lu. The hyperfine parameters obtained with a consistent model that considers both the easy magnetization direction and the titanium preferential site occupancy are discussed as a function of rare-earth atomic number, temperature and hydrogen content. The average hyperfine fields in the RFe11Ti and RFe11TiH compounds are described with a two-sublattice model in which the iron sublattice contributions coincide with the fields observed in LuFe11Ti and LuFe11TiH, respectively. In both series, the rare-earth sublattice contributes a transferred field which occurs as a result of indirect exchange between the rare-earth 4f and iron 3d electrons and depends on the nature of the rare-earth element. The increase in average hyperfine field and isomer shift upon hydrogenation of the RFe11Ti compounds results from the unit-cell expansion upon hydride formation. The observed average quadrupole shift is closely related to the magnetic anisotropy exhibited by each compound.




French National Center for Scientific Research
National Science Foundation of Belgium
Belgium. Ministry of the French Speaking Community
National Science Foundation (U.S.)
University of Li`ege

Document Type

Article - Journal

Document Version


File Type





© 2006 Institute of Physics - IOP Publishing, All rights reserved.