EPR spectra of Gd³⁺-doped NdCl₃·6H₂O and PrCl₃·7H₂O

Abstract

The paramagnetic resonance spectra of Gd³⁺-doped NdCl₃·6 H₂O and PrCl₃·7 H₂O single crystals are studied at room temperature. A six-line spectrum for H ‖ Z and a seven-line spectrum for H ‖ X corresponding to ΔM=±1 transitions, are observed in the case of Gd³⁺-doped NdCl₃−6 H₂O, whereas Gd³⁺-doped PrCl₃−7 H₂O shows a seven-line spectrum for H ‖ Z as well as for H ‖ X. The absence of the seventh line in the case of Gd³⁺-doped NdCl₃·6 H₂O for H ‖ Z spectrum is explained as due to large zero-field splitting between ±5/2 and ±7/2 levels. The angular variation of the observed spectra in ZX plane from θ=0° to θ=90° is studied and the spin-Hamiltonian analysis is presented. A number of lines have been observed in the low-field region in the case of Gd³⁺-doped PrCl₃·7 H₂O and they have been analyzed as due to transitions with ΔMϡ.