Abstract:
In this thesis different connections between free energy of the magnetic
crystal and the Hamiltonian of the rare earth is established, Anisotropy
energy transform
form dependence on the direction cosines to
dependence on the spherical angle ( , ∅ ) to formula defines the
anisotropy Constants. equation connect between anisotropy constant and
anisotropy coefficient has be found .
Application of these formulas to case of heavy rare earth was done . The
crystal field parameters have been calculated for rare earth elements by
means of point charge model.
Anisotropy constant was calculated for Terbium (Tb) using the exception
value of the Steven operators and values of crystal filed obtained.
Anisotropy coefficients was found using the formulism connection. The
result obtained has good agree with the experimental data.
