Related Experiment Video
Updated: Jul 30, 2025

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
Shaping Perpendicular Magnetic Anisotropy of Co2MnGa Heusler Alloy Using Ion Irradiation for Magnetic Sensor
Anmol Mahendra1,2,3, Peter P Murmu2, Susant Kumar Acharya1,3
1Robinson Research Institute, Victoria University of Wellington, Wellington 6140, New Zealand.
Abstract:
Magnetic sensors are key elements in many industrial, security, military, and biomedical applications. Heusler alloys are promising materials for magnetic sensor applications due to their high spin polarization and tunable magnetic properties. The dynamic field range of magnetic sensors is strongly related to the perpendicular magnetic anisotropy (PMA). By tuning the PMA, it is possible to modify the sensing direction, sensitivity and even the accuracy of the magnetic sensors. Here, we report the tuning of PMA in a Co2MnGa Heusler alloy film via argon (Ar) ion irradiation. MgO/Co2MnGa/Pd films with an initial PMA were irradiated with 30 keV 40Ar+ ions with fluences (ions·cm-2) between 1 × 1013 and 1 × 1015 Ar·cm-2, which corresponds to displacement per atom values between 0.17 and 17, estimated from Monte-Carlo-based simulations. The magneto optical and magnetization results showed that the effective anisotropy energy (K) decreased from ~153 kJ·m-3 for the un-irradiated film to ~14 kJ·m-3 for the 1 × 1014 Ar·cm-2 irradiated film. The reduced K and PMA are attributed to ion-irradiation-induced interface intermixing that decreased the interfacial anisotropy. These results demonstrate that ion irradiation is a promising technique for shaping the PMA of Co2MnGa Heusler alloy for magnetic sensor applications.
Related Concept Videos
Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
Diamagnetism
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Ferromagnetism
Paramagnetism
π Electron Effects on Chemical Shift: Overview
Diamagnetic Shielding of Nuclei: Local Diamagnetic Current

