ELECTRICAL PROPERTIES OF AN AMORPHOUS ZIRCONIUMOXIDE THIN FILM AND STRUCTURE FORMATION DURING CRYSTALLIZATION

摘要

Metastable amorphous oxides with a strong oxygen deficiency often show surprising phenomena upon relaxation into thermodynamically stable phases. For example, Nagarajan et al. found a new type of chemically driven insulator-metal transition in highly non-stoichiometric gallium oxide films (GaO_x).[1] Here, an internal solid-state disproportionation reaction leads to the growth Ga_2O_3 nuclei in the initially insulating GaO_x matrix which thereby attains metal-like conductivity. Moreover, it has been recently shown that such films can act as memristive switches. [2]. Highly non-stoichiometric titania (TiO_(1.6)) films show a similar disproportionation reaction upon heating but as the phase diagram for this material is more complex, various phases can be found during the relaxation [3].