Effect of oxygen on the molten BGO/Ir wetting and sticking

Abstract

In order to better understand the BGO-crucible interaction, the wetting of the molten BGO on Ir substrates has been studied by the sessile drop method at 1050 °C. It was found that the oxygen partial pressure in the surrounding atmosphere is an important parameter. For $P_{{{\text{O}}_{ 2} }}$ > 0.1 mbar, full wetting is observed without any visible contact angle. X-ray diffraction analyses have shown that Bi₂Ir₂O₇ is formed at the interface. For $P_{{{\text{O}}_{ 2} }}$ < 0.1 mbar, a drop is observed with a contact angle of 70° and no chemical reaction is detected. Attempts to grow BGO samples under low oxygen partial pressure resulted in ingot without sticking with the crucible.