Of course, I have XRD for magnetite. I found that checking the stability of the material can be an interesting experiment, and because I get the TiO2-Fe3O4 oxide system I can not use nitric acid because it dissolves TiO2. Hence the idea for H2O2 which is a strong oxidant.
I have little material, so it's important for me if my idea is good or bad. I would not want to waste it.