Abstract: Electron spin resonance spectra of amorphous Li⁺ conductor B₂O₃-0.7Li₂O-0.7LiCl-xAl₂O₃-0.1V₂O₅ (x=0.05 and 0.15) have been studied. It is found that (1) The ESR spectra is Gaussian type and the addition of V₂O₅ is suitable; (2) The hyperfine structure is due to the complex ions VO²⁺ which possess tetragonal symmetry and belong to group C_4v. Parallel and perpendicular principal components of the hyperfine-coupling tensor, A_//=0.0175cm^-1 and A_⊥=0.0063cm^-1. Calculation from g_// and g_⊥ shows that the energy difference between the gound state ²B_2g and the first excited state ²E_g, △₁=2.46×104cm^-1,the energy difference between ²B_2g and the second state ²B_1g,△₂=3.03×104cm^-1; (3) The ESR spectra from 295°to 440°K show that ESR intensity of the glass with less content of Al₂O₃ (0.05mol.) is 3-2 times higher than that of the glass with more content of Al₂O₃ (O.15mol.); The more the content of Al₂O₃, the less the drop of ESR intensity with increasing temparature.

Key words: Fast ionic conductor, Hyperfine structure, ESR spectra at various temperatures