Dual current-perpendicular-to-plane giant magnetoresistive sensors for magnetic recording heads with reduced sensitivity to spin-torque-induced noise
Dual current-perpendicular-to-plane giant magnetoresistive sensors for magnetic recording heads with reduced sensitivity to spin-torque-induced noise
复制标题
用于磁记录头的双电流垂直于平面的巨磁阻传感器，对自旋扭矩引起的噪声的敏感性降低
DOI：
10.1063/1.2165930
复制
发表时间：
2006
影响因子：
3.2
通讯作者：
N. Smith
中科院分区：
文献类型：
--
作者：
J. Childress;M. Carey;S. Kiselev;J. Katine;S. Maat;N. Smith
双IrMn钉扎电流垂直于平面的巨磁阻传感器结构进行了研究，其信号和噪声特性进行了比较，类似的标准单传感器，使用测试结构的尺寸下降到50 nm。在单自旋阀和双自旋阀之间，发现本征信号ΔRA乘积增加了近2倍，尽管由于第二个80 nm厚的IrMn钉扎层堆叠引起的寄生电阻将ΔR scinR的净增加限制为1.5倍。对于具有反平行自由层和参考层的单自旋阀，噪声功率谱密度显示出正电流和负电流之间的大的不对称性，这是由于对于大于1×107A scincm 2的正电流密度（电子从参考层流向自由层）的强自旋扭矩效应。然而，对于双传感器，临界电流密度在极性上是对称的，并且增加到5×107A scincm 2以上，导致实际传感器输出电压增加5倍。
Dual IrMn-pinned current-perpendicular-to-plane giant magnetoresistive sensor structures have been investigated, and their signal and noise characteristics are compared to similar standard single sensors, using test structures with sizes down to 50nm. The intrinsic signal ΔRA product is found to be increased by a factor of nearly 2 between single and dual spin valves, although the parasitic resistance due to the second 80-nm-thick IrMn-pinned layer stack limits the net increase in ΔR∕R to a factor of 1.5. For the single spin valve with antiparallel free and reference layers, the noise power spectral density shows a large asymmetry between positive and negative current flows due to strong spin-torque effects for positive (electrons flow from reference layer to free layer) current densities above 1×107A∕cm2. For the dual sensor, however, the critical current density is symmetric in polarity and is increased to above 5×107A∕cm2, resulting in a 5-fold increase in practical sensor output voltage.