OK fedi hivemind... I'm looking for a flat square of material about 1cm on a side and maybe 1mm thick that is going to survive being boiled in hot nitric/sulfuric acid for a couple of minutes, then rinsed in acetone and water.
I'm thinking a glass or ceramic, but don't have a source for ready made chunks of the right size (microscope coverglasses are too fragile).
You can get pre-diced silicon wafers with chunks the right size (e.g. Ted Pella 16006) but that's annoyingly expensive. Anything more cost effective?
Also related... I need to mount a sample to this substrate with something that isn't going to disintegrate during this etching process lol. (good luck)