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

Here we investigate the temperature dependence of anomalous Hall effect in Hf/GdFeCo/MgO sheet film and Hall bar device. The magnetic compensation temperature (T-comp) for the sheet film and device is found to be similar to 240 K and similar to 118 K, respectively. In sheet film, spin-flopping is witnessed at a considerably lower field, 0.6 T, close to T-comp. 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 T-comp. Moreover, the temperature-dependent anomalous Hall resistance (R-AHE) responds unusually when a perpendicular magnetic field is applied while recording the R-AHE. The zero-field R-AHE scan suggests the Hall signal generates solely from the FeCo moment. However, the behavior of 3T-field R-AHE scan in which the R-AHE drops close to zero near the T-comp 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.

Automated summary

The study investigates the temperature dependence of anomalous Hall effect in Hf/GdFeCo/MgO sheet film and Hall bar device, revealing similar magnetic compensation temperatures of around 240 K and 118 K. The experiment shows distinct characteristics of AHE hysteresis loops in the sheet film and device, as well as unusual responses in temperature-dependent anomalous Hall resistance when subjected to a perpendicular magnetic field. These findings provide important insights into understanding the complex AHE behavior of ferrimagnets for spintronic applications.