Structural and ferromagnetic properties of Cu-doped GaN
2007 (English)In: Journal of Materials Research, ISSN 0884-2914, Vol. 22, no 5, 1396-1405 p.Article in journal (Refereed) Published
The wurtzite polymorph of GaN was calcined with CuO in flowing nitrogen. As a result of this processing, both superconducting quantum interference device magnetometry and ferromagnetic resonance studies showed ferromagnetism in these samples at room temperature. These magnetic results are qualitatively consistent with very recent first-principle calculations [Wu et al., Appl. Phys. Lett. 89, 062505 (2006)] that predict ferromagnetism in Cu-doped GaN. We focus in this paper on analyzing changes in the GaN atomic and electronic structure due to calcination with CuO using multiple analytical methods. Quantitative powder x-ray diffraction (XRD) showed changes in the lattice constants of the GaN due to the incorporation of copper (and possibly oxygen). Energy-dispersive x-ray spectroscopy proved the incorporation of copper into the GaN crystal structure. Electron-gun monochromated electron energy loss spectroscopy showed CuO calcinations-induced GaN band gap changes and indicated changes in the atomic arrangements due to the calcination process. The fine structure of the N K-edge showed differences in the peak ratios with respect to higher nominal CuO contents, corresponding to an increase in the c-lattice constant as confirmed by XRD.
Place, publisher, year, edition, pages
2007. Vol. 22, no 5, 1396-1405 p.
room-temperature ferromagnetism, energy-loss spectroscopy, diluted, magnetic semiconductors, zno thin-films, spintronics, oxide, bulk, gamnn, aln
IdentifiersURN: urn:nbn:se:kth:diva-16607DOI: 10.1557/jmr.2007.0168ISI: 000246258300041ScopusID: 2-s2.0-34250181235OAI: oai:DiVA.org:kth-16607DiVA: diva2:334649
QC 201005252010-08-052010-08-05Bibliographically approved