Abrupt suppression of the exchange bias across a non-magnetic insulator spacer

作者：Nicolodi S^*; Harres A; Pereira L G; Schmidt J E; de Sousa M A; Pelegrini F; Viegas A D C; Deranlot C; Petroff F; Geshev J

来源：Journal of Applied Physics, 2011, 110(6): 063922.

DOI：10.1063/1.3642090

This paper reports results obtained on exchange-biased IrMn/Al(2)O(3)/Co films deposited by magnetron sputtering, where the thickness of the non-magnetic insulator layer, (t)Al(2)O(3), was varied. Ferromagnetic resonance and static magnetization measurements were used to study the exchange interaction between the antiferromagnet (IrMn) and ferromagnet (Co) layers. X-ray diffractometry and x-ray reflectometry as well as high-resolution transmission electron microscopy were employed for structural characterization of the films. It was found that the IrMn/Co exchange coupling decreases very abruptly with (t)Al(2)O(3) being the exponential decay length at least four times smaller than the values previously reported for exchange-bias systems. Such a rapid suppression of the coupling is explained in terms of the prompt loss of the direct contact between the antiferromagnet and the ferromagnet with (t)Al(2)O(3).

• 出版日期2011-9-15