BIPOLAR THRESHOLD SWITCHING IN VANADATE GLASSES

I-V characteristics are found for switching devices prepared from two-component vanadate glasses. Besides V//2O//5 they contain an oxide of a transition element or an oxide of another two-valent, three-valent or four-valent element as second component. It is established that using high concentrations of V//2O//5 (above 50 mol%) is possible to prepare threshold switches which possess stable characteristics. It is shown that by increasing the temperature, the threshold power P//t//h decreases linearly and tends to zero at approximately the temperature T//t of the metal-semiconductor phase transition. An attempt is made to describe the switching using a model in which the electrostatic field increases the number of nuclei of the metal-like phase and when the nuclei concentration reaches the percolation concentration the device switches on.