TY - JOUR
T1 - Improvement of the detectivity in an Fe-Sn magnetic-field sensor with a large current injection
AU - Shiogai, Junichi
AU - Jin, Zhenhu
AU - Satake, Yosuke
AU - Fujiwara, Kohei
AU - Tsukazaki, Atsushi
N1 - Funding Information:
The authors thank M. Oogane and Y. Ando at Tohoku University for fruitful discussion and noise spectral measurement, and they acknowledge the stimulated discussion in the meeting of the Cooperative Research Project of the Research Institute of Electrical Communication, Tohoku University. This work was partly supported by CREST (No. JPMJCR18T2), the Japan Science and Technology Agency. We thank NEOARK Corporation for the photolithography equipment for device fabrication.
Publisher Copyright:
© 2022 The Japan Society of Applied Physics.
PY - 2022/5
Y1 - 2022/5
N2 - 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.
AB - 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.
KW - Fe-Sn thin film device
KW - Noise spectral density
KW - anomalous Hall effect
KW - magnetic-field sensor
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U2 - 10.35848/1347-4065/ac465a
DO - 10.35848/1347-4065/ac465a
M3 - Article
AN - SCOPUS:85127348198
SN - 0021-4922
VL - 61
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
IS - SC
M1 - SC1069
ER -