The influence of the crystal‐to‐glass transition on the local structure in semiconducting compounds and alloys such as As2S3, As2Se3, As2Te3, AsSI, AsSeI, As4Te5I2, As2Se3 · As2Te3, Ge15Te85, and As4Ge15Te81 is analysed by Mössbauer spectroscopy for nuclei of 125Te, 127I, 129Te(129I), and 119Sn and by measuring the chemical shift of the AsLα1 line. It is shown that for such compounds and alloys as As2Te3, As4Te5I2, Ge15Te85, As4Ge15Te81 the transition into the glassy state may take place only under conditions of severe quenching. For such semiconductors the crystal‐to‐glass transition is accompanied by a change in the symmetry of the local environment of the tellurium, iodine, and germanium atoms. A correlation between the change in the electric conductivity and density and the change in the local structure at the crystal‐to‐glass transition is observed.

The conduction and transport numbers of charge carriers for composites in the systems MeWO 4 -WO 3 (Me = Ca, Sr, Ba) are studied as a function of the temperature and the activity of oxygen in a gas phase. The transport numbers are determined by an emf method and are estimated from dependences of conductance on the activity of oxygen in a gas phase. The deficiencies of the given procedure as applied to investigation of properties of composite phases are analyzed. The materials under study are classified with a class of metacomposites. The concentration intervals of the ionic, mixed, and electronic conductions are determined. The conduction of composites of compositions (100 -ı )å WO 4 · ı WO 3 is predominantly ionic at x ≤ 10 (Me = Ca), x ≤ 60 (Me = Sr), and x ≤ 45 (Me = Ba). The obtained data are explained in the framework of a model that represents a composite as a distributed matrix system where a film of surface phase MeW-s with a high mobility of oxygen ions plays the role of a connected matrix. It is presumed that the surface phase MeW-s possesses double-sided surface activity ( α å W -s ≤ , ) and a higher mobility with respect to å WO 4 and WO 3 . The discovered anomalies of dependences ( í ) and partial dependences , σ el ( T ) are explained by a change in the stoichiometry, morphology, and the degree of connectedness of surface phase MeW-s caused by with a change in the temperature and composition of composites.

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