https://doi.org/10.1140/epjb/e2005-00073-y
Epitaxial growth and magnetic exchange anisotropy in Fe3O4/NiO bilayers grown on MgO(001) and Al2O3(0001)
1
CEMES-CNRS, 29 rue J. Marvig, BP 94347, 31055 Toulouse Cedex, France
2
LNMO, 135 avenue de Rangueil, 31077 Toulouse Cedex 4, France
Corresponding author: a snoeck@cemes.fr
Received:
15
September
2004
Revised:
10
December
2004
Published online:
15
March
2005
Epitaxial Fe3O4/NiO bilayers were epitaxially grown on MgO(001) and Al2O3(0001) substrates to investigate the influence of the fully spin compensated (001) and the non-compensated (111) NiO interface planes between the ferromagnetic (F) and antiferromagnetic (AF) layers on the AF/F exchange coupling. Bilayers of different magnetite thicknesses and constant NiO thickness were investigated. The structural characterizations indicate a perfect epitaxy of the two layers for the both growth directions in the two Fe3O4/NiO/MgO(001) and NiO/Fe3O4/Al2O3(0001) systems. An epitaxial ferrimagnetic (Ni,Fe)Fe2O4 phase is observed at the AF/F interface when the NiO oxide is grown on the top of the Fe3O4 layer while a perfectly flat AF/F interface is observed in the Fe3O4/NiO/MgO(001) system exhibiting only a very slight interdiffusion. Magnetic measurements indicate a relative strong bias at 300 K for the bilayers grown on Al2O3(0001), which decreases with the inverse of the ferrimagnetic layer thickness as theoretically expected. On the contrary, a zero exchange biasing is observed at 300 K for the bilayers grown on MgO(001).
PACS: 61.16.-d – Electron, ion, and scanning probe microscopy / 68.55.-a – Thin film structure and morphology / 75.50.Ee – Antiferromagnetics / 75.50.Gg – Ferrimagnetics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005