Transition from soft to hard ferrite in Co1-xMgxFe2O4 nanoparticles: Cation distribution, magnetic and magneto-optical properties. - Ivanova, O.; Edelman, I.; Thakur, P.; Molokeev, M.; Zharkov, S.; Knyazev, Y.; Dubrovskiy, A.; Sukhachev, A.; Ivantsov, R.; Zeer, G.; Thakur, A. (Journal of Magnetism & Magnetic Materials, 2026)