# What category do Gd3Fe2Fe3O12 belong?

After polishing my $\ce{GdFe2}$ sample with silicon carbide emery paper it developed trace amount of $\ce{Gd3Fe2Fe3O12}$ on the surface. Why is it being formed, are these type of compounds called anything?

• Is this something you've actually done? If so, how do you know that this is the exact compound being formed? Jun 30 '17 at 16:36
• @chipbuster Yes I am currently doing this in my summer internship. I know that this exact compound is being formed because I performed grazing incidence X-ray diffraction and while indexing the diffractogram I came to know this. Jun 30 '17 at 16:43
• Formula isn't correct and why wouldn't it be simple corrosion. Jun 30 '17 at 20:16
• @Mithoron I did the analysis (indexing) using computer program and this formula is the correct one. Can you please explain further how can corrosion form a complex compound like this. My doubt is that why the presence of this compound is not detected before polishing in either powder or GI XRD and what exactly happened during polishing that led to the formation of it. Jun 30 '17 at 20:36
• You'd need to mark Fe as II and III to be correct. It's just some mixed oxide. Jun 30 '17 at 20:48