We are preparing Zn ferrites nanoparticles. I have been surprised to detect that they were transformed into hematite + Zn oxide by simple calcination in air.

Thanks to your answers on this web site, I have found a very detailled publication and thermodynamic data about this phase transformation but the reported necessary temperatures are well above the ones that we use in our Laboratory. No more than 900°C.

Do you know if this temperature will be enough with nanoparticles ? Do you have experiences in this field that can help us? Do we nead to treat under air/O2 or Argon?