Size Effect and Temperature of Magnetic Ordering in ε-Fe2O3 Nanoparticles
Balaev, D.A., Semenov, S.V., Dubrovskiy, A.A., (...), Shaykhutdinov, K.A., Martyanov, O.N.// Journal of Superconductivity and Novel Magnetism//
https://doi.org/10.1007/s10948-025-07025-3
The magnetization of a series of samples containing ε-Fe2O3 nanoparticles of different average sizes (approximately 4‒11 nm) has been measured in the temperature range of 300–550 K, which includes the region of a high-temperature magnetic transition. The observed Néel temperature drop has been attributed to the manifestation of the size effect: from ~ 500 K for fairly coarse (> 10 nm) particles to ~ 450 K for particles of ~ 5 nm in size. The obtained particle size dependence of the Néel temperature has been analyzed within the scaling law for critical phenomena in finite-size systems.