Teja Mittireddi, RaviRaviTeja MittireddiKumar Singh, RanjanRanjanKumar SinghPanda, EmilaEmilaPanda2025-08-312025-08-312023-08-1510.1016/j.jmmm.2023.1709662-s2.0-85163511826https://d8.irins.org/handle/IITG2025/26677Ternary Sm-Pr-Co magnets with CaCu<inf>5</inf>-type hexagonal structure exhibit superior magnetic properties and investigating their oxidation behavior is crucial for assessing their stability under the service conditions. In this regard, here thermal oxidation of sintered SmPrCo<inf>5</inf> magnet is carried out by varying the oxidation temperature from 373 to 973 K for 5 hr under atmospheric pressure. Owing to their lower negative Gibbs free energy, rare earth oxides of Sm<inf>2</inf>O<inf>3</inf> and Pr<inf>2</inf>O<inf>3</inf> are found to initially form, making cobalt free from SmPrCo<inf>5</inf> lattice. Cobalt is then observed to migrate to the oxide surface, because of the difference in chemical potential between the surface and inner layers, leading to Co<inf>3</inf>O<inf>4</inf> formation. Moreover, here a comprehensive discussion on the occurrences of different oxide phases and their depth distributions in the oxide layer are being made. Finally, a correlation between these oxide phases and the alterations in their magnetic properties is discussed.falseMagnetic properties | Microstructure | Oxidation | Permanent magnet | SmPrCo5Article15 August 20232170966arJournal1WOS:001054044500001