NiFe/CoFe/Cu/CoFe/MnIr spin valves studied by ferromagnetic resonance

作者：Timopheev A A^*; Sobolev N A; Pogorelov Y G; Bunyaev S A; Teixeira J M; Cardoso S; Freitas P P; Kakazei G N

来源：Journal of Applied Physics, 2013, 113(17): 17D713.

DOI：10.1063/1.4798615

Ion-beam deposited (Glass/Ta/NiFe/CoFe/Cu/CoFe/MnIr/Ta) spin valves (SVs) with a Cu-spacer thickness (t(Cu)) varying from 14 to 28 angstrom have been studied by ferromagnetic resonance (FMR) and magnetoresistance (MR) measurements. With respect to the interlayer coupling strength between the free and fixed ferromagnetic layers, the samples have been divided in those with a weak coupling (for t(Cu) %26gt; 16 angstrom) and a strong coupling regimes (for t(Cu) %26lt;= 16 angstrom). The FMR behavior in these two regimes is quite different. For the weakly coupled series, there are two well-defined FMR peaks stemming from the free and fixed layers. Their in-plane angular dependences exhibit 180 degrees and 360 degrees symmetries, respectively. For the strongly coupled SVs, the resonance modes are hybridized and possess features of both layers simultaneously. The main coupling mechanism between the two layers, as concluded from the FMR and MR measurements, is the Neel %26quot;orange-peel%26quot; magnetostatic interaction, accompanied by a direct exchange due to pinholes in the Cu spacer for t(Cu) %26lt; 17 angstrom.

• 出版日期2013-5-7