VP14-09 Reversible Sign Change in the Anomalous Hall Effect Induced by Strain
Creators: Toshiaki Morita
Tomohiro Koyama and Daichi Chiba
Publisher: name: IEEE
Year: 2025

The anomalous Hall effect (AHE) is a fundamental physics related to spin-dependent transport. It is reported that a sign change of the AHE depending on the temperature and the layer structure [1,2]. The origin of the sign change of the AHE is attributed to band filling effect [3]. Recently, flexible spintronics utilizing the inverse magnetostriction effect has attracted attention [4]. The magnetostriction effect is a well-known phenomenon that combines strain and magnetism, but the modulation of magnetism by strain is still not fully understood. In this study, we observed reversible sign change of the AHE induced by strain in Co/Ni multilayered film. We deposited a [Co/Ni]n multilayer on a flexible substrate by magnetron sputtering. Hall measurement was conducted without (w/o) and with (w/) application of a uniaxial strain in various temperatures. The small tensile jig was used to apply a strain. The results of Hall measurement at 260 K are shown in Figure 1. Blue and red plots represent the results w/o and w/ strain, respectively. In w/o strain, the sign of the AHE is positive; saturation value of Hall resistance (RsH) is positive under positive magnetic field. In contrast, in w/ strain, the sign of the AHE reverses to negative. When the strain is removed, the sign of the AHE returns to positive (dashed blue plot). Figure 2 shows the temperature dependence of RsH w/o and w/ strain. The temperature at which the sign of the AHE changes is around 210 K w/o strain. When strain is applied, the sign of the AHE changes around 270 K. The datas suggest that band filling can be reversibly controlled by strain. We will discuss in more detail the effect of strain on the sign change in the AHE. The authors thank S. Ota for technical support. This work is supported by Program for Leading Graduate School: “Interactive Materials Science Cadet Program”, JSPS KAKENHI (Grant No. 24KJ1613 and 23H00183), JST A-Step (Grant No. JPMJTR233A), JST CREST (Grant No. JPMJCR20C6), MEXT X-NICS, and the Spintronics Research Network of Japan.References: [1] Z.B. Guo, W.B. Mi and R.O. Aboljadayel et al., Phys. Rev, B Vol. 86, p.104433 (2012). [2] V. Keskin, B. Aktas and J. Schmalhorst et al., Appl. Phys. Lett. Vol. 102, p.022416 (2013). [3] I. Turek J. Kudrnovský and V. Drchal Phys. Rev. B Vol. 86, p.014405 (2012). [4] S. Ota, A. Ando and D. Chiba Nat. Electron. Vol. 1, p.124 (2018).
The anomalous Hall effect (AHE) is a fundamental physics related to spin-dependent transport. It is reported that a sign change of the AHE depending on the temperature and the layer structure [1,2]. The origin of the sign change of the AHE is attributed to band filling effect [3]. Recently, flexible spintronics utilizing the inverse magnetostriction effect has attracted attention [4]. The magnetostriction effect is a well-known phenomenon that combines strain and magnetism, but the modulation of magnetism by strain is still not fully understood. In this study, we observed reversible sign change of the AHE induced by strain in Co/Ni multilayered film. We deposited a [Co/Ni]n multilayer on a flexible substrate by magnetron sputtering. Hall measurement was conducted without (w/o) and with (w/) application of a uniaxial strain in various temperatures. The small tensile jig was used to apply a strain. The results of Hall measurement at 260 K are shown in Figure 1. Blue and red plots represent the results w/o and w/ strain, respectively. In w/o strain, the sign of the AHE is positive; saturation value of Hall resistance (RsH) is positive under positive magnetic field. In contrast, in w/ strain, the sign of the AHE reverses to negative. When the strain is removed, the sign of the AHE returns to positive (dashed blue plot). Figure 2 shows the temperature dependence of RsH w/o and w/ strain. The temperature at which the sign of the AHE changes is around 210 K w/o strain. When strain is applied, the sign of the AHE changes around 270 K. The datas suggest that band filling can be reversibly controlled by strain. We will discuss in more detail the effect of strain on the sign change in the AHE. The authors thank S. Ota for technical support. This work is supported by Program for Leading Graduate School: “Interactive Materials Science Cadet Program”, JSPS KAKENHI (Grant No. 24KJ1613 and 23H00183), JST A-Step (Grant No. JPMJTR233A), JST CREST (Grant No. JPMJCR20C6), MEXT X-NICS, and the Spintronics Research Network of Japan.References: [1] Z.B. Guo, W.B. Mi and R.O. Aboljadayel et al., Phys. Rev, B Vol. 86, p.104433 (2012). [2] V. Keskin, B. Aktas and J. Schmalhorst et al., Appl. Phys. Lett. Vol. 102, p.022416 (2013). [3] I. Turek J. Kudrnovský and V. Drchal Phys. Rev. B Vol. 86, p.014405 (2012). [4] S. Ota, A. Ando and D. Chiba Nat. Electron. Vol. 1, p.124 (2018).