Exchange biased magnetoelectric composites for magnetic field sensor application by frequency conversion
Exchange biased magnetoelectric composites for magnetic field sensor application by frequency conversion
复制标题
DOI：
10.1063/1.4913814
复制
发表时间：
2015-05-07
影响因子：
3.2
通讯作者：
Meyners, D.
中科院分区：
文献类型：
--
作者：
Roebisch, V.;Yarar, E.;Meyners, D.
比较了交换偏置耦合和非交换偏置耦合下基于AlN和FeCoSiB的磁电复合传感器。所有叠层均采用薄膜沉积法在Si衬底上制备。而没有交换偏置的传感器在谐振交流场的1 pT/根Hz范围内表现出较低的检测极限，这种传感器在检测低频信号时失败。因此，对于频率为10hz、积分时间为3s的交变磁场，其检测限提高到约10nt /根Hz。基于传感器的磁调制的变频技术将其检测极限提高了约一个数量级。然而，频率转换可以更有效地应用于具有交换偏置多层作为磁致伸缩相的磁电传感器。因此，对于10 Hz信号，它们的检测极限约为180 pT/根Hz，积分时间为1 s。这与两种类型传感器的磁电系数（ME）形成对比。对于非偏置复合材料和谐振场，alpha（ME）等于6.9 kV/cm Oe，而对于交换偏置复合材料，alpha（ME）要小8倍。尽管如此，就低频磁场的检测极限而言，传感器性能的提高可以用交换偏置传感器调制期间显著降低的磁噪声贡献来解释。(c) 2015 AIP出版有限责任公司
A comparison is presented between magnetoelectric composite sensors based on AlN and FeCoSiB with and without exchange bias coupling. All layer stacks were fabricated by thin film deposition on Si substrates. Whereas sensors without exchange bias exhibit a low limit of detection in the 1 pT/root Hz regime for resonant AC fields, such sensors fail at the detection of low frequency signals. Accordingly, their detection limit increases to about 10 nT/root Hz for alternating magnetic fields with 10 Hz frequency and an integration time equal to 3s. A frequency conversion technique based on magnetic modulation of the sensors improves their detection limit by about one order of magnitude. However, frequency conversion can be applied more effectively to magnetoelectric sensors with exchange biased multilayers as a magnetostrictive phase. As a result, their limit of detection is about 180 pT/root Hz for 10 Hz signals and an integration time of 1 s. This is in contrast to the magnetoelectric coefficient alpha(ME) of the two types of sensors. Whereas alpha(ME) equals 6.9 kV/cm Oe for non-biased composites and resonant fields, it is by a factor of 8 smaller for the exchange biased composites. The nonetheless arising improvement of sensor performance with regard to the limit of detection for magnetic fields with low frequencies can be explained by a significantly lower magnetic noise contribution during modulation of the exchange biased sensors. (c) 2015 AIP Publishing LLC.