Studies of the electrodes of electroformed metal-SiO/BaO-metal thin film structures by means of optical and scanning electron microscopy provide evidence of the formation of conducting filaments in such structures. An explanation of the formation and subsequent operation of such structures as negative resistance and electron-emitting devices includes an electrolytic process along the filaments involving the liberation of oxygen gas at the anode.

Observations of local defects caused by electrical conduction through thin sandwich structures of AgSiO/BaOAg

Thermal stability and crystallization kinetics of As14Ge14Se72−xSbx (where x = 3, 6, 9, 12 and 15 at.%) glasses are studied by the differential scanning calorimetry. The values of the glass transition temperature (Tg) and the peak temperature of crystallization (Tp) are found to be dependent on heating rate and antimony content. From the heating rate dependence of Tg and Tp the values of the activation energy for glass transition (Et) and the activation energy for crystallization (Ec) are evaluated and their composition dependence discussed. Crystallization studies have been made under non-isothermal conditions with the samples heated at several uniform rates. Using a recent analysis developed for non-isothermal crystallization studies, information on some aspects of the crystallization process has been obtained. The stability calculations emphasized that the thermal stability decreases with increasing the Sb content.

Thermal stability and crystallization kinetics of new As–Ge–Se–Sb glasses

This paper presents the results of kinematical studies of glass transition and crystallization in glassy Se85-xTe15Sbx (x = 2, 4, 6 and 8) using differential scan- ning calorimetry (DSC). From the dependence on heating rates of, the glass transition temperatures (Tg), and tem- perature of crystallization (Tp) the activation energy for glass transition (Eg) and the activation energy for crystal- lization (Ec) are calculated and their composition depen- dence can be discussed in term of the average coordination number and cohesive energy. The thermal stability of Se85-xTe15Sbx was evaluated in terms of criterion DT = Tc - Tg and kinetic criteria K(Tg) and K(Tp). By analyzing the crystallization results, the crystallization mechanism is characterized. Two (two- and three-dimensional growth) mechanisms are working simultaneously during the amor- phous-crystalline transformation of the Se83Te15Sb3 alloy while only one (three-dimensional growth) mechanism is responsible for the crystallization process of the chalcog- enides Se85-xTe15Sbx (x = 4, 6 and 8) glass. The phases at which the alloy crystallizes after the thermal process have been identified by X-ray diffraction.

Thermal stability and crystallization kinetics of ternary Se–Te–Sb semiconducting glassy alloys

I-V studies indicate a composition dependent switching behavior (Memory or Threshold) in bulk Al20AsxTe80−x glasses, which is determined by the coordination and composition of aluminum. Investigations on temperature and thickness dependence of switching and structural studies on switched samples suggest thermal and electronic mechanisms of switching for the memory and threshold samples, respectively. The present results also show that these samples have a wider composition range of threshold behavior with lower threshold voltages compared to other threshold samples.

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Composition tunable memory and threshold switching in Al20As xTe80− x semiconducting glasses

http://eli.kau.edu.sa/Files/0057296/Researches/57804_27978.pdf

Thermal stability of Ge-As-Te-In glasses

Memory (lock-on) phenomena observed in semiconducting glasses of the AsTeGe system have been investigated by electrical, calorimetrical and X-ray methods. Some differences between the memory process observed in high-As glasses and that in low-As glasses have been shown, which include both the waiting time for the process and the growth behaviour of the conductive filament formed between the electrodes. A strong correlation between the waiting time and the crystallization rate has also been indicated for their dependences on both the composition of the glass and the temperature. Finally, the kinetics of growth of the conductive filament during the memory process has been discussed using a simplified model, based on the ionic behaviour of the constituent elements in switch-on plasma, which explains well the polarity dependence of the filament growth.

M. Sugi

Papers

Kinetics of growth of conductive filament in AsTeGe glasses