RT Journal Article T1 Interface double-exchange ferromagnetism in the Mn-Zn-O system: New class of biphase magnetism A1 García, M. A.. A1 Ruiz González, María Luisa A1 Quesada, A. A1 González Calbet, José María A1 Hernando Grande, Antonio AB In this Letter, we experimentally show that the room temperature ferromagnetism in the Mn-Zn-O system recently observed is associated with the coexistence of Mn^(3+) and Mn^(4+) via a double-exchange mechanism. The presence of the ZnO around MnO_2 modifies the kinetics of MnO_2 →Mn_2O_3 reduction and favors the coexistence of both Mn oxidation states. The ferromagnetic phase is associated with the interface formed at the Zn diffusion front into Mn oxide, corroborated by preparing thin film multilayers that exhibit saturation magnetization 2 orders of magnitude higher than bulk samples. PB American Physical Society SN 0031-9007 YR 2005 FD 2005-06-03 LK https://hdl.handle.net/20.500.14352/52098 UL https://hdl.handle.net/20.500.14352/52098 LA eng NO ©2005 The American Physical Society.This work has been partially supported by the University Complutense Project No. PR1/05-13325. Partial support from the EU Network of Excellence SANDIE is also acknowledged. NO University Complutense de Madrid NO EU Network of Excellence SANDIE DS Docta Complutense RD 4 abr 2025