NMR Study on the Chemical Bonding and the Ionic Conductivity in Noble Metal Halides

抄録

The temperature dependence of nuclear relaxation rate, 1/T₁ has been measured for copper halides, CuX with X being Cl, Br and I. The results are interpreted in terms of the quadrupole relaxation due to lattice vibrations and defect motions. The data of 1/T₁ are compared with a model calculation based on an ionic model, in which the degree of covalent bonding λ₀ is estimated to be 63% for CuCl, 49% for CuBr and 27% for CuI. The λ₀ values for copper halides are compared with previous values for silver and sodium halides, and also compared with the ionicity of A^NB^8-N binary compounds. The relation between λ₀ values and migration energies E_m for cation vacancies derived from 1/T₁ data is discussed in connection with the superionicity of α-AgI.