%0 Journal Article %T Low-Symmetry Spin Hamiltonian and Crystal Field Tensors Analysis: Fe3+ in Natrolite %+ Kazan State University (KPFU) %+ Institut des Sciences de la Terre d'Orléans (ISTO) %A Vinokurov, V. M. %A Gaite, Jean-Michel %A R. Bulka, G. %A M. Khasanova, N. %A M. Nizamutdinov, N. %A A. Galeev, A. %A Rudowicz, C. %< avec comité de lecture %@ 1090-7807 %J Journal of Magnetic Resonance %I Elsevier %V 155 %P (1) 57-63 %8 2002 %D 2002 %R 10.1006/jmre.2002.2512 %K natrolite %K spin Hamiltonian %K low symmetry effect %K crystal field %K tensor invariants %Z Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]Journal articles %X Electron paramagnetic resonance study of a natural single crystal of natrolite was carried out at the frequency ν=36.772 GHz at room temperature. The angular dependence of the four symmetry-related spectra of Fe3+ in the three crystallographic planes was fitted to a spin Hamiltonian (S=5/2) of symmetry Ci. The rank 4 crystal field tensors at tetrahedral sites were calculated using the point-charge model to determine the principal axes orientations of their cubic and trigonal components. The analysis of zero-field splitting tensors and comparison with crystal field ones suggests that Fe3+ substitutes for Al3+ with no significant distortion of the coordination tetrahedron in natrolite. Comparison of data for several natural and synthetic crystals reveals that the 4-rank zero-field splitting tensor invariants for Fe3+ at the tetrahedral oxygen-coordinated sites are distinguishably smaller than those for Fe3+ at octahedral sites. Such comparative analysis may help to determine the substitutional sites in other crystals. %G English %L hal-00076878 %U https://insu.hal.science/hal-00076878 %~ INSU %~ CNRS %~ UNIV-ORLEANS %~ ISTO %~ OSUC