Difference between Blocking and Néel Temperatures in the Exchange Biased Fe₃₄/CoO System

Authors

• P. J. van der Zaag
• Yumi Ijiri, Oberlin CollegeFollow
• Julie A. Borchers
• L. F. Feiner
• R. M. Wolf
• J. M. Gaines
• R. W. Erwin
• M. A. Verheijen

Abstract

The blocking temperature 𝑇_B has been determined as a function of the antiferromagnetic layer thickness in the Fe₃O₄/CoO exchange biased system. For CoO layers thinner than 50 Å, 𝑇_B is reduced below the Néel temperature 𝑇_N of bulk CoO (291 K), independent of crystallographic orientation or film substrate ( 𝛼−Al₂O₃, SrTiO3, and MgO). Neutron diffraction studies show that 𝑇_B does not track the CoO ordering temperature and, hence, that this reduction in 𝑇_B does not arise from finite-size scaling. Instead, the ordering temperature of the CoO layers is enhanced above the bulk 𝑇_N for layer thicknesses ≲100Å due to the proximity of magnetic Fe₃O₄ layers.

Repository Citation

van der Zaag, P.J., Y. Ijiri, A. Borchers, et al. 2000. "Difference between Blocking and Néel Temperatures in the Exchange Biased Fe₃₄/CoO System." Physical Review Letters 84(26): 6102-6105.

Publisher

American Physical Society

Publication Date

6-1-2000

Publication Title

Physical Review Letters

Department

Physics and Astronomy

Document Type

Article

DOI

https://dx.doi.org/10.1103/PhysRevLett.84.6102

Language

English

Format

text