Spin waves in exchange-biased NiFe∕IrMn circular nanorings
Spin waves in exchange-biased NiFe∕IrMn circular nanorings
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DOI：
10.1063/1.2829597
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发表时间：
2008-01
影响因子：
3.2
通讯作者：
S. Tacchi;M. Madami;G. Gubbiotti;G. Carlotti;W. Jung;C. Ross
中科院分区：
文献类型：
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作者：
S. Tacchi;M. Madami;G. Gubbiotti;G. Carlotti;W. Jung;C. Ross
对NiFe(20 Nm)/IrMn(5 Nm)环的静态和动态特性进行了实验研究。磁光克尔效应测量表明，IrMn在≈80Oe处引入了相当大的交换偏置磁场，使磁滞回线沿偏置方向移动。使用微磁计算(包括HEB的存在)令人满意地再现了测量的环。用布里渊光散射对高频简正模的测量表明，IrMn层的存在导致了自旋波频率的整体上移，这与以往对其他交换偏置系统的研究定性一致。此外，外场反转时自旋波频率的频率不对称性与克尔效应测量到的交换偏置场的存在是定量一致的。
We present the experimental investigation of the static and dynamical properties of NiFe(20nm)∕IrMn(5nm) rings. Magneto-optic Kerr effect measurements show that the IrMn introduces a sizable exchange-bias field HEB≈80Oe, which shifts the hysteresis loop along the excange-bias direction. Measured loops were satisfactorily reproduced using a micromagnetic calculation which includes the presence of HEB. Measurement of high frequency normal modes, by Brillouin light scattering, shows that the presence of the IrMn layer causes an overall up-shift of the spin wave frequency, in qualitative agreement with pervious studies of other exchange-biased systems. Moreover, the frequency asymmetry of the spin wave frequency upon reversing the external field is quantitatively consistent with the presence of the exchange-bias field measured by the Kerr effect.