Studies on electrical switching behavior of As-Te-Tl glasses – effect of local structure on switching type and composition dependence of switching voltages

Bulk As-Te-Tl glasses belonging to the As₃₀Te_70-xTl_x (4≤x≤22) and As₄₀Te_60-xTl_x (5≤x≤20) composition tie lines are studied for their I–V characteristics. Unlike other As-Te-III glasses such as As-Te-Al and As-Te-In, which exhibit threshold behavior, the present samples show memory switching. The composition dependence of switching voltages (V_t) of As-Te-Tl glasses is also different from that of As-Te-Al and As-Te-In glasses, and it is found that V_t decreases with the addition of Tl. Both the type of switching exhibited by As-Te-Tl glasses and the composition dependence of V_t, seems to be intimately connected with the nature of bonding of Tl atoms and the resultant structural network. Furthermore, the temperature and thickness dependence of switching voltages of As-Te-Tl glasses suggest an electro thermal mechanism for switching in these samples. PACS 71.55.Jv; 61.43Fs; 61.43.-j; 72.80.Ey; 73.61.Jc