Room-Temperature Exchange-Coupled Nanometer-Thick ZnFe2O4 and SrFe12O19 Bilayers: Implications for Spintronics and Exchange-Spring Magnets

Exchange-spring ZnFe2O4/SrFe12O19 (ZNF/SFO) bilayers were investigated to explore interfacial exchange coupling and dynamic magnetic response by varying the nanometer-scale thickness of the top ZNF layer. Room-temperature M–H loops exhibit two-step reversal (HCsoft 65 Oe and HChard 5.6 kOe) and magn...

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Detalles Bibliográficos
Autor: Grammatikopoulos, Panagiotis
Tipo de recurso: artículo
Fecha de publicación:2026
País:España
Institución:Universidad de Castilla-La Mancha
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:dnet:ruidera_____::56fb92d14a7bb8b76f47ba96e7a25061
Acceso en línea:https://doi.org/10.1021/acsanm.5c05613
https://hdl.handle.net/10578/48200
Access Level:acceso abierto
Palabra clave:Exchange-spring system
Ferrite heterostructures
Ferromagnetic resonance
Interfacial coupling
Micromagnetic simulations.
Descripción
Sumario:Exchange-spring ZnFe2O4/SrFe12O19 (ZNF/SFO) bilayers were investigated to explore interfacial exchange coupling and dynamic magnetic response by varying the nanometer-scale thickness of the top ZNF layer. Room-temperature M–H loops exhibit two-step reversal (HCsoft 65 Oe and HChard 5.6 kOe) and magnetic stiffening (Hk = 7.5 kOe) with a 59/41 hard/soft phase ratio, confirming strong exchange coupling. X-band FMR (9.5 GHz) shows a reduced resonance field (Hr = 2456 Oe) and doubled effective magnetization (4pMeff 1.9 kG) compared to single ZNF films. Micromagnetic simulations using optimized parameters (MS = 473 kA/m, A = 1.2 × 10–11 J/m, K = 0.53 kJ/m3) reproduce experimental trends, revealing efficient torque transfer and coherent interfacial coupling. These results establish that MS, A, and K, respectively, govern coupling strength, torque transmission, and coercivity, positioning ZNF/SFO bilayers as promising rare-earth-free materials for high-energy-density magnetic and spintronic devices.