Nuclear magnetic resonance of ⁷Li in LiB₃O₅ crystal and glass

The spin lattice relaxation rates and the absorption spectra of ⁷Li in both LiB₃O₅ crystal and glass samples were measured from room temperature up to 800 K. At low temperatures the dominant contribution to the relaxation rates was due to the spin–phonon interaction in both samples. For the crystal the relaxation caused by the diffusion of Li ions became significant above 580 K, and the narrowing of the absorption line started at about 540 K. For the glass the narrowing of the line started at room temperature and the effect of the diffusion of Li ions on the relaxation rate appeared above 400 K. From these results the correlation time τ_c of the fluctuating field at Li nuclei was obtained. Each value of the activation energy of τ_c deduced from the relaxation rate and the narrowing of the line, respectively, agreed well.