ESR Line Shape Due to Anisotropic α-Fluorine Coupling in the Polycrystalline State

Abstract

The ESR line shape due to an anisotropic hyperfine coupling was calculated including the nuclear Zeeman term in the spin Hamiltonian. Since it was desirable to see the effect of the nuclear Zeeman term explicitly, the line shape was calculated for the ideal case where the component linewidth is infinitesimally small. In such a case, it was possible to derive the shape function analytically for an axially symmetric hyperfine tensor, and even for an orthorhombic symmetry the numerical integration in the line-shape function was not so difficult. The numerical calculation was executed for the α-fluorine coupling with the tensor elements of 189, −4, and −16 G, and the result was compared with the simpler cases in which the nuclear Zeeman term is neglected.