[Ifeffit] Question about Air sensitive sample holder

Hello, Our group (Jerry Seidler) just started a project involving doing VTC and HERFD on Yb doped CrX3 material. They are thin small crystal sheets and are very air sensitive. We have tried encapsulated them between a layer of laptop tape and film, but after 12hr we see degradation due to air leaks. I am looking for some advice on air sensitive sample holder. What are some typical methods you use to deal with air sensitivity, especially for samples in thin sheets geometry? Thank you