J. Phys. I France 5 (1995) 1281-1300
A simple Derivation of the Tunneling Splitting for Large Quantum SpinsFrançoise Hartmann-Boutron
Laboratoire de Spectrométrie Physique (UJF-CNRS, UA 08), Université J. Fourier/Grenoble I, B.P. 87, 38402 Saint-Martin d'Hères Cédex, France
(Received 8 June 1995, received and accepted in final form 6 July 1995, )
With the help of a pertubation treatment to lowest order, general expressions for the tunneling splitting have been derived for a quantum spin S. This spin is assumed to have a main axial Hamiltonian (without applied longitudinal magnetic field), and to be submitted to perturbations with orthorhombic, tetragonal, trigonal or hexagonal symmetries, or to a transverse field. The formulas obtained are valid for general (not very small) S. They are compared with available results of the literature. Previous observations of tunneling splittings in terbium compounds by EPR are mentioned, with the relevant references.
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