Characterization of n-GaN dilute magnetic semiconductors by cobalt ions implantation at high-fluence

In this study, we present the structural and magnetic characteristics of cobalt ions implantation at a high-fluence (5×1016 cm−2) into n-GaN epilayer of thickness about 1.6 μm. The n-GaN was grown on sapphire by metal organic chemical vapor deposition (MOCVD). Rutherford backscattering channeling was used for the structural study. After implantation, samples were annealed at 700, 800 and 900 °C by rapid thermal annealing in ambient N2. XRD measurements did not show any secondary phase or metal related-peaks. High resolution X-ray diffraction (HRXRD) was performed as well to characterize structures. Well-defined hysteresis loops were observed at 5 K and room temperature using alternating gradient magnetometer AGM and Superconducting Quantum Interference Device (SQUID) magnetometer. Temperature-dependent magnetization indicated magnetic moment at the lowest temperatures and retained magnetization up to 380 K for cobalt-ion-implanted samples.

▸ Experiment started with MOCVD grown semiconducting material GaN. ▸ GaN was implanted with cobalt ions (Co+) of dose 5×1016 cm−2 at room temperature. ▸ Structural characterization was performed by RBS, XRD and HR-XRD. ▸ Magnetic properties were observed by AGM and SQUID measurements. ▸ High TC dilute magnetic semiconductors has been observed up to 380 K for cobalt implanted GaN at high-fluence (5×1016 cm−2).