Nearly Constant Loss in Lithium and LiCl-doped Borate Glasses

Measurements of the complex dielectric permittivity (Li(2)O)(x)(B(2)O(3))(100-x) and halide-doped (Li(2)O)(x) (LiCl)(y)(B(2)O(3))(100-x-y) glasses conducted in the nearly constant loss (NCL) regime at low temperatures are reported. Scaling properties reveal that the NCL in (LiO)(x)(B(2)O(3))(100-x) is largely ionic in origin for these materials and increases in proportion to the Li(2)O content. However, at low Li(2)O content, the NCL becomes dominated by a non-ionic loss arising from the borate network or other impurity polarizations. Halide doping is seen to produce an additional enhancement of the NCL that is consistent with its known enhancement of the bulk conduction.