Spin characterization of lanthanoid ion Eu2+ (S-8(7/2)) in a CaF2 single crystal by electron spin transient nutation spectroscopy

One of lanthanoid ions, Eu2+ (S-8(7/2)), doped in a CaF2 single crystal wit h cubic symmetry has been studied by an Electron Spin Transient Nutation (E STN) method of pulsed ESR spectroscopy. In a two-dimensional ESTN spectrum of the Eu2+ ion, the nutation frequencies indicated the dependence of hyper fine ESR transitions as well as of spin quantum number S and M-S manifolds. It is demonstrated that the 2D-ESTN method discriminates the hyperfine all owed ESR transitions from the hyperfine forbidden ones. Such discrimination of the ESR transitions enables us to make facile assignments of complicate d ESR spectra. The nutation frequencies observed for the hyperfine allowed / forbidden transitions were quantitatively understood with the help of red uced rotation matrix elements.