We recently succeeded in fabricating new LiNbO3-type ferrites, ScFeO3 and InFeO3, at 15 GPa and 1450 ºC. For ScFeO3, the idea of stabilizing the LiNbO3-type structure follows a previous attempt to prepare the ¿polar¿ corundum-type ScFeO3 at 6 GPa and 1500 ºC, but the synthesis at higher pressure enable us to obtain the polar oxide different from ¿polar¿ corundum. For these polar and magnetic materials, the unambiguous determination of the crystal and magnetic structures is an obvious priority. Our preliminary neutron diffraction data confirmed the feasibility of detecting the magnetic peaks even for 20-mg sample due to the large Fe3+ moment. We here request 3 days on WISH to measure the temperature-variable neutron diffraction to resolve any subtle changes in the crystal structure linked to the onset of long-range magnetic order and the critical nature of the transition.