Energy storage and liberation of vibro-milled γ-Fe2O3

Publisher Website
Google Scholar
Abstract
Energy is stored in γ‐Fe2O3 during preliminary vibro‐milling. The stored energy, detected from differential scanning calorimetry, amounted to up to twice as much as the reported heat of transformation to α‐Fe2O3 and is associated with the formation of the amorphous phase. The amount of transformation at the first step of annealing was parallel to the stored energy. Energy liberation on annealing occurs competitively through recovery or recrystallization and transformation into the α‐phase. At temperatures lower than 400 °C, recovery favorably occurs, whereas above 400 °C, transformation predominantly takes place. The lattice disturbance in vibro‐milled γ‐Fe2O3 does not recover completely before the completion of the transformation to the α‐phase.