Low‐field magnetic sensors based on the planar Hall effect
Low‐field magnetic sensors based on the planar Hall effect
复制标题
DOI：
10.1063/1.113697
复制
发表时间：
1995-05
影响因子：
4
通讯作者：
A. Schuhl;F. Dau;J. Childress
中科院分区：
文献类型：
--
作者：
A. Schuhl;F. Dau;J. Childress
基于平面霍尔效应，研制了灵敏的磁场检测器件。该活性材料由坡莫合金薄膜（6 nm厚）通过分子束外延外延生长。通过与在MgO（001）上外延生长的Fe/Pd双层的铁磁耦合，在薄膜中感应出单轴磁各向异性。有源层显示磁阻比ΔR/R= 2%。该器件的灵敏度为100 V/TA，最小可检测场低于10 nT。检测器响应在至少四十年内是线性的。横向电阻率只对各向异性电阻率项敏感，而对各向同性电阻率项不敏感，各向同性电阻率项对温度敏感性很高。因此，与类似的纵向磁阻检测器相比，1Hz处的热噪声降低了四个数量级。
Sensitive magnetic field detection devices have been fabricated based on the planar Hall effect. The active material consists of permalloy ultrathin films (6 nm thick) epitaxially grown by molecular beam epitaxy. Uniaxial magnetic anisotropy is induced in the film through ferromagnetic coupling with a Fe/Pd bilayer epitaxially grown on MgO(001). The active layer shows a magnetoresistive ratio ΔR/R=2%. The device gives a sensitivity of 100 V/TA and a minimum detectable field below 10 nT. The detector response is linear over at least four decades. The transverse resistivity is sensitive only to the anisotropic resistivity, and not to the isotropic resistivity term which is highly temperature sensitive. Consequently, the thermal noise at 1 Hz is reduced by four orders of magnitude compared to a similar longitudinal magnetoresistive detector.