Cristobalite growth inhibitor in Pyrex borosilicate glass—gallium oxide

The effect of gallium oxide on cristobalite formation in Pyrex borosilicate glass has been studied. XRD results show that with 20 vol.% gallium oxide, the precipitation of cristobalite at 800 °C is completely prevented. This result is further evidenced by the linear thermal expansion measurement, in which, in contrast to the system without a sufficient amount of gallium oxide (0–10 vol.%), the thermal expansion coefficient of the composite with 20 vol.% gallium oxide remains unchanged with sintering time at the temperature investigated and, moreover, is very close to the theoretically calculated value.