Improvement of the detectivity in an Fe-Sn magnetic-field sensor with a large current injection

Junichi Shiogai, Zhenhu Jin, Yosuke Satake, Kohei Fujiwara, Atsushi Tsukazaki

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


A ferromagnetic nanocrystalline Fe-Sn is an excellent platform for magnetic-field sensor based on anomalous Hall effect (AHE) owing to simple fabrication and superior thermal stability. For improvement of the magnetic-field sensitivity, doping impurity and increasing injection current are effective approaches. However, in the light of magnetic-field detectivity, the large current may increase the voltage noise. In this study, a maximum allowable current was improved by employing the overlayer electrode configuration on a Ta-doped Fe-Sn AHE sensor. In noise measurements, the 1/f noise becomes significant with increasing the current at low frequency, resulting in saturation of the detectivity to 240 nTHz-1/2 at 120 Hz. At high frequency, the detectivity reaches 48 nTHz-1/2 at 3.1 mA showing ten times improvement of the detectivity compared with the non-doped Fe-Sn AHE sensor. Material design and device structure optimization will accelerate further improvement of the sensing properties of the Fe-Sn-based AHE sensor.

Original languageEnglish
Article numberSC1069
JournalJapanese journal of applied physics
Issue numberSC
Publication statusPublished - 2022 May


  • Fe-Sn thin film device
  • Noise spectral density
  • anomalous Hall effect
  • magnetic-field sensor

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


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