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Magnetic properties of Cu-doped GaN grown by molecular beam epitaxy

Ganz, Philipp R.; Fischer, Gerda; Sürgers, Christoph; Schaadt, Daniel M.

Abstract: Cu-doped GaN films were epitaxially grown by molecular beam epitaxy on C-plane sapphire substrates with an AlN buffer layer. Growth under metal-rich and nitrogen-rich conditions was investigated for different Cu-to-Ga beam-equivalent-pressure ratios x BEP. The samples were characterized by scanning electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffraction. Films within a narrow range of x BEP around 1% exhibit ferromagnetic behavior with a Curie temperature higher than 400 K. For higher x BEP1%, islands of a Cu-Ga compound are predominantly formed at the surface as nonferromagnetic precipitates. Our detailed study shows that the saturation magnetization of ferromagnetic films with x BEP 1% decreases with increasing film thickness. This suggests that the ferromagnetism arises from defects, such as threading dislocations, created by the incorporation of Cu into the GaN.


Zugehörige Institution(en) am KIT Physikalisches Institut (PHI)
Publikationstyp Zeitschriftenaufsatz
Jahr 2012
Sprache Englisch
Identifikator DOI: 10.1103/PhysRevB.85.165204
ISSN: 1098-0121
KITopen ID: 1000050401
Erschienen in Physical Review B - Condensed Matter and Materials Physics
Band 85
Heft 16
Seiten Art.-Nr. 165204
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