Electron Spin Resonance of Nd³⁺ in Cadmium Sulfide Single Crystals

The electron spin resonance study of Nd 3+ in cadmium sulfide single crystal has been done at 1.4°K and X-band. The observed spectra consist of a strong line due to even isotopes and satellite lines coming from the hyperfine interaction with nuclei of odd isotopes. They can be explained by using the spin Hamiltonian, \(H{=}g//β HzSz+g_{}β(HₓSₓ+HySy)+AIzSz+B(IₓSₓ+IySy)\) where the c -axis of thecrystal is chosen as the z -axis. The parameters are g // =0.43±0.05, g ⊥ =3.409±0.005, | B |=(342±5)×10 -4 cm -1 for 143 Nd, and | B |=(213±3)×10 -4 cm -1 for 145 Nd. The crystal field around Nd 3+ in cadmium sulfide has the symmetry of C 3 v . The ground state ( 4 I 9/2 ) splits into five doublets by this crystal field. Judd's theory of Nd 3+ in double nitrate is applied to this case to discuss the ground state of Nd 3+ in cadmium sulfide. The ground state wave function is constructed as a linear combination, 0.2490|9/2, \({∓}5/2{>}{±}0.9685|9/2\), ±1/2>. Besides Nd 3+ resonance lines, several lines have been observed. Paramagnetic centers which are responsible for these lines are discussed.