INFLUENCE OF THE NANOSTRUCTURE OF TANTALUM OXIDE ON THE FLARE CHARACTER OF ITS ELECTROLUMINESCENCEWITH ANODIC-ELECTROLYSIS FORMATION IN CHEMICALLY PURE WATER

Theoretical and experimental studies were carried out to identify the reasons for the flash nature of the combustion of electroluminescence (EL) of tantalum oxide (Ta2O5), formed in chemically pure (distilled) water during high-voltage anodization of 1700 s. Nonlinear growth of the Ta2O5 film during this time was established, and a polychrome effect was discovered for its thicknesses from 150 ± 28 nm to 820 ± 80 nm. At the same time, EL ignition begins at an oxide thickness of 390 ± 74 nm, which corresponds to an anodization time of 78 ± 15 s, and from 968 ± 185 s until the end of this process, bright EL flashes are observed. Their luminosity can reach 2.8·10–3 lm/m2. It is shown that the cause of the outbreaks is explosive processes in dynamically changing Ta2O5 pores ranging in size from tens of nanometers to several micrometers and containing gas-discharge plasma from various products of electro- and plasma-chemical reactions with a temperature of the order of 12000 K, created due to Joule heating by the flowing current. It has been established that the formation of the plasma itself occurs as a result of electrical breakdown in pores, the field strength in which can reach the order of 3·108 V/m or more.