Experimental evidence of Ga-vacancy induced room temperature ferromagnetic behavior in GaN films

Journal Article · Mon Oct 17 00:00:00 EDT 2011 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3654151· OSTI ID:22027782

Roul, Basanta; Kumar, Mahesh ^[1]; Rajpalke, Mohana K; Bhat, Thirumaleshwara N; Krupanidhi, S B ^[1]; Kalghatgi, A T ^[2]; Kumar, Nitesh; Sundaresan, A ^[3]

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1. Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India)
2. Central Research Laboratory, Bharat Electronics, Bangalore 560013 (India)
3. Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064 (India)

We have grown Ga deficient GaN epitaxial films on (0001) sapphire substrate by plasma-assisted molecular beam epitaxy and report the experimental evidence of room temperature ferromagnetic behavior. The observed yellow emission peak in room temperature photoluminescence spectra and the peak positioning at 300 cm{sup -1} in Raman spectra confirms the existence of Ga vacancies. The x-ray photoelectron spectroscopic measurements further confirmed the formation of Ga vacancies; since the N/Ga is found to be >1. The ferromagnetism is believed to originate from the polarization of the unpaired 2p electrons of N surrounding the Ga vacancy.

• OSTI ID: 22027782
• Journal Information: Applied Physics Letters, Vol. 99, Issue 16; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTAL GROWTH
CRYSTALS
FERROMAGNETIC MATERIALS
FERROMAGNETISM
GALLIUM NITRIDES
LAYERS
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
PLASMA
POLARIZATION
RAMAN SPECTRA
SAPPHIRE
SEMICONDUCTOR MATERIALS
SUBSTRATES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
VACANCIES
X-RAY PHOTOELECTRON SPECTROSCOPY