Hi List members,

does anyone know a few things about tungsten oxide? I am intersted in the
dielectric constant of it.
The problem is, as im trying to get the tungsten oxide out of a tungsten tip
by oxidizing it in nitric acid. This reaction shuts down at a certain
thickness of the oxide layer, as the oxide forms a passivation layer. Thus, I
need to know the following data:

1. How long does the etch process take, until the passivation thickness of the
oxide layer is reached?

2. How thick will the layer then be?

3. What is the dielectrical constant of tungsten oxide (WO3)?

Thanks for your help in advance.

Regards, Tom