Spin-flop led peculiar behavior of temperature-dependent anomalous Hall effect in Hf/Gd-Fe-Co

• Published in: Journal of magnetism and magnetic materials 2021-11, Vol.537, p.168196, Article 168196
• Main Authors: Bhatt, Ramesh Chandra, Ye, Lin-Xiu, Hai, Ngo Trong, Wu, Jong-Ching, Wu, Te-ho
• Format: Article
• Language: English
• Subjects: Airline security; Anomalous Hall effect; Compensation; Electromagnetism; Ferrimagnets; Gadolinium; GdFeCo ferrimagnet; Hall contribution; Hall effect; Hysteresis loops; Spin-flop transition; Temperature dependence
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2021.168196

•Temperature dependent anomalous Hall effect (AHE) in GdFeCo.•Magnetic compensation temperature for sheet film ~240 K and device ~118 K.•In sheet film, spin-flopping is witnessed at 0.6 Tesla close to compensation temperature.•Triple loops are observed in AHE hysteresis for the device.•The zero-field and 3 Tesla RAHE scan suggests the Hall signal generates solely from the FeCo moment.•Drop in the 3Tesla RAHE near the compensation is explained by considering the low field spin-flopping. Here we investigate the temperature dependence of anomalous Hall effect in Hf/GdFeCo/MgO sheet film and Hall bar device. The magnetic compensation temperature (Tcomp) for the sheet film and device is found to be ~240 K and ~118 K, respectively. In sheet film, spin-flopping is witnessed at a considerably lower field, 0.6 T, close to Tcomp. The AHE hysteresis loops in the sheet film have a single loop whereas in the Hall bar device, hystereses consist of triple loops are observed just above the Tcomp. Moreover, the temperature-dependent anomalous Hall resistance (RAHE) responds unusually when a perpendicular magnetic field is applied while recording the RAHE. The zero-field RAHE scan suggests the Hall signal generates solely from the FeCo moment. However, the behavior of 3T-field RAHE scan in which the RAHE drops close to zero near the Tcomp seems to be following the net magnetization response of the device, is explained by considering the low field spin-flopping around the compensation temperature. The results presented here give important insight to understand the complex AHE behavior of ferrimagnets for their spintronic applications.