The study of the imprint mold materials suited for B₂O ₃-La₂O₃ based glass

Reactivity between nanoimprint mold material and optical glass has been investigated by measuring the contact angle between these materials in a nitrogen atmosphere at high temperature up to 1000 °C. Since the low softening temperature optical glass was chosen in this study, the thermal upper limit of the contact angle measurement was set 800 °C on. As the mold materials, electrodeposits Ni-W alloy containing 40 wt% W and the glass like carbon (GC) were chose. In the case of the GC, the contact angle did not changed largely at the temperatures up to 800 °C, while obvious reactant phase in the interface layer between GC and the molten glass was observed. In the case of the Ni-W alloy, the contact angle decreased with increasing the temperature while, no reactant phase was observed at the interface. This indicated that indicating the Ni-W alloy is suitable as the mold materials for the B ₂O₃-La₂O₃ based optical glass.