The glass formation regions are determined in the Ga2S3-GeS2-MCl (M = Li, N
a, K, Cs, Ag, T1) and GaI3-NaCl systems. It is noted that the formation of
complex structural units such as MGaS3/2Cl is favourable for increasing the
glass-forming regions. Temperature dependencies of the electric conductivi
ty of 60 samples in the system Ga2S3-GeS2-MCl were measured. All of these g
lasses have cation conductivity. Activation energy of conductivity for all
investigated systems is a linear function on the cubic root of the atomic f
raction of cations. These results correspond to the simple model of cation
conductivity. (C) 1999 Elsevier Science B.V. All rights reserved.