A solvothermal transformation of α-Fe2O3 nanocrystals to Fe3O4 polyhedrons

Highly dispersed Fe3O4 polyhedrons have been fabricated through the solvothermal transformation of α-Fe2O3 nanocrystals. The shapes, sizes, and surface characteristics of the Fe3O4 polyhedrons can be facilely controlled. The growth route is confirmed as the process of “dissolution–reduction–recrystallization”. The saturation magnetization of as-prepared Fe3O4 reaches 102.2 emu g−1.