Temperature dependence of the switching field in all-perpendicular spin-valve nanopillars

D. B. Gopman (1) , D. Bedau (1, 2) , G. Wolf (1) , Stéphane Mangin (3) , E. E. Fullerton (4) , J. A. Katine (2) , A. D. Kent (1)

1 Department of Physics [New York]
2 HGST San Jose Research Center
3 IJL - Institut Jean Lamour
4 UC San Diego - University of California [San Diego]

We present temperature dependent switching measurements of the Co/Ni multilayered free element of 75-nm-diameter spin-valve nanopillars. Angular dependent hysteresis measurements as well as switching field measurements taken at low temperature are in agreement with a model of thermal activation over a perpendicular anisotropy barrier. However, the statistics of switching (i.e. the mean switching field and the variance of the switching field distribution) from 20 up to 400 K are in disagreement with a Neel-Brown model that assumes a temperature independent barrier height and anisotropy field. We introduce a modified Neel-Brown model that fits the experimental data in which we attribute a T-3/2 dependence to the barrier height and the anisotropy field due to the temperature dependent magnetization and anisotropy energy.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

D. B. Gopman, D. Bedau, G. Wolf, Stéphane Mangin, E. E. Fullerton, et al.. Temperature dependence of the switching field in all-perpendicular spin-valve nanopillars. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2013, 88 (10), ⟨10.1103/PhysRevB.88.100401⟩. ⟨hal-01276629⟩