| Paper Abstract and Keywords |
| Presentation |
2026-06-04 15:15
Fabrication of Co-Pt/Ru/Co-Pt films with perpendicular magnetization, low saturation magnetic field, and high saturation magnetization for realization of novel magnetic field sensors with high sensitivity, high signal output, and low power consumption
Hiiro Abe, Soichi Tanaka, Genta Egawa, Satoru Yoshimura (Akita Univ.) |
| Abstract |
(in Japanese) |
(See Japanese page) |
| (in English) |
A novel magnetic field sensor consisting of a BiFeO₃ (BFO)-based ferromagnetic/ferroelectric thin film and a metallic perpendicular soft magnetic thin film is proposed by us to realize high sensitivity, high signal output, and low power consumption. In this magnetic field sensor, even with a small applied external magnetic field, the magnetization direction of the BFO-based thin film is controlled by magnetization transfer using the stray field generated from the perpendicular soft magnetic thin film. Therefore, it is necessary to fabricate a thick metallic perpendicular soft magnetic thin film with high saturation magnetization, low saturation magnetic field, and perpendicular magnetization. In our previous study, [Co-Pt/Pt/Co-Pt]ₙ multilayers with high saturation magnetization and perpendicular magnetic anisotropy were successfully fabricated with a total thickness of 20 nm. However, the saturation magnetic field remained as high as approximately 2.0 kOe, which is still insufficient for low-field operation. In this study, Co-Pt/Ru/Co-Pt multilayers were fabricated to reduce the saturation magnetic field by introducing interlayer ferromagnetic coupling via the RKKY interaction. As a function of Ru layer thickness, the saturation magnetic field exhibited oscillatory behavior, indicating periodic changes in interlayer exchange coupling. At a Ru thickness of 1.4 nm, strong ferromagnetic coupling was achieved, resulting in a reduction in saturation magnetic field to 1.2 kOe. Furthermore, microfabrication down to a device size of 3 μm revealed that low saturation magnetic field and low coercivity were maintained, suggesting that multidomain structures and domain-wall-driven magnetization reversal are preserved for the device with 3 μm size. On the other hand, in thicker multilayer structures ([Co-Pt/Ru]ₙ/Co-Pt), increasing the number of layers resulted in non-uniform interlayer coupling, where ferromagnetic and antiferromagnetic coupling coexisted. This led to non-coherent magnetization reversal and an increase in the saturation magnetic field. These results indicate that Co-Pt/Ru/Co-Pt multilayers are promising as a material for this magnetic field sensors, while precise control of interlayer coupling uniformity is essential for further reduction of the saturation magnetic field. |
| Keyword |
(in Japanese) |
(See Japanese page) |
| (in English) |
Co-based alloy thin films / multilayer films / saturation magnetization / saturation magnetic field / perpendicular magnetic anisotropy / magnetic field sensor / / |
| Reference Info. |
ITE Tech. Rep., vol. 50, no. 15, MMS2026-38, pp. 7-14, June 2026. |
| Paper # |
MMS2026-38 |
| Date of Issue |
2026-05-28 (MMS) |
| ISSN |
Online edition: ISSN 2424-1970 |
| Download PDF |
|
| Conference Information |
| Committee |
IEICE-MRIS MMS TOHOKU |
| Conference Date |
2026-06-04 - 2026-06-05 |
| Place (in Japanese) |
(See Japanese page) |
| Place (in English) |
RIEC, Tohoku Univ. |
| Topics (in Japanese) |
(See Japanese page) |
| Topics (in English) |
Recording System, Head, Medium + General |
| Paper Information |
| Registration To |
MMS |
| Conference Code |
2026-06-MRIS-MMS-TOHOKU |
| Language |
Japanese |
| Title (in Japanese) |
(See Japanese page) |
| Sub Title (in Japanese) |
(See Japanese page) |
| Title (in English) |
Fabrication of Co-Pt/Ru/Co-Pt films with perpendicular magnetization, low saturation magnetic field, and high saturation magnetization for realization of novel magnetic field sensors with high sensitivity, high signal output, and low power consumption |
| Sub Title (in English) |
|
| Keyword(1) |
Co-based alloy thin films |
| Keyword(2) |
multilayer films |
| Keyword(3) |
saturation magnetization |
| Keyword(4) |
saturation magnetic field |
| Keyword(5) |
perpendicular magnetic anisotropy |
| Keyword(6) |
magnetic field sensor |
| Keyword(7) |
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| Keyword(8) |
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| 1st Author's Name |
Hiiro Abe |
| 1st Author's Affiliation |
Akita University (Akita Univ.) |
| 2nd Author's Name |
Soichi Tanaka |
| 2nd Author's Affiliation |
Akita University (Akita Univ.) |
| 3rd Author's Name |
Genta Egawa |
| 3rd Author's Affiliation |
Akita University (Akita Univ.) |
| 4th Author's Name |
Satoru Yoshimura |
| 4th Author's Affiliation |
Akita University (Akita Univ.) |
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| Speaker |
Author-1 |
| Date Time |
2026-06-04 15:15:00 |
| Presentation Time |
25 minutes |
| Registration for |
MMS |
| Paper # |
MMS2026-38 |
| Volume (vol) |
vol.50 |
| Number (no) |
no.15 |
| Page |
pp.7-14 |
| #Pages |
8 |
| Date of Issue |
2026-05-28 (MMS) |
|