Defect–defect magnetic coupling in Gd doped GaN epitaxial films: A polarization selective magneto-photoluminescence study
| Autor: | Poulab Chakrabarti, Rajendra K. Saroj, Subhabrata Dhar, Preetha Sarkar, Swarup Deb |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Photoluminescence Materials science Physics and Astronomy (miscellaneous) Condensed matter physics Scattering Doping 02 engineering and technology 021001 nanoscience & nanotechnology Epitaxy Polarization (waves) 01 natural sciences Inductive coupling Magnetic field Condensed Matter::Materials Science 0103 physical sciences 0210 nano-technology Saturation (magnetic) |
| Zdroj: | Applied Physics Letters. 117:022108 |
| ISSN: | 1077-3118 0003-6951 |
| Popis: | Here, we have carried out a magnetic field dependent polarization selective photoluminescence (PL) study at 1.5 K on Gd-doped GaN epitaxial layers grown on c-SiC substrates, where the incorporation of Gd has been found to generate three types of defects, which results in bound excitonic features in low temperature PL spectra. The study reveals that the external magnetic field dependence of the spin-flip scattering rates for the three excitonic features shows an increasing tendency of saturation at high fields as the density of these defects increases in these layers. This suggests that the signals must be stemming from defects which are ferromagnetically coupled with each other. This is further confirmed by the study carried out on a GaN sample co-doped with Si and Gd, where defects are found to be ferromagnetically coupled, while the Si-donors do not. |
| Databáze: | OpenAIRE |
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