Tuning Anomalous Hall Signal by Deposition Parameters in Hf/Gd-Fe-Co Bilayer Sheet Films

Tuning Anomalous Hall Signal by Deposition Parameters in Hf/Gd-Fe-Co Bilayer Sheet Films

Here we report the influence of deposition parameters on the magnetic properties of Hf/Gd-Fe-Co sheet films. Samples were grown in a magnetron sputtering where the target's power, pre-sputtering time and power, and capping layer were varied to find the stable perpendicular magnetic anisotropy (PMA) in the series. The magnetic properties of the sheet films were investigated using anomalous Hall effect measurements. It is observed that the Gd-Fe-Co with different Gd-compositions at a fixed FeCo-power exhibit better PMA at 135 W than the 200 W of FeCo. For samples with a MgO capping layer, the magnetic compensation point decreases from 135 W to 105 W (Gd-power), when FeCo-power is decreased from 200 W to 135 W. Moreover, the coercivity vs Gd-power plot diverges at the compensation point which shows an ideal behavior. Similar results are observed with the SiN capping layer with a compensation point at around 85 W. The pre-sputtering time of the targets is also a determining factor of AHE properties, and the longer the time is the better. Furthermore, target cleaning at larger pre-sputtering power reproduces the compensation point around 95 W. These results show ways to achieve the desired PMA and reproducible compensation in the Gd-Fe-Co films, which are potential candidates for the magnetic memory elements.