Probing local order in (Ga,Mn)N alloys by X-ray absorption spectroscopy

The structure of Mn clusters in ͑Ga,Mn͒N and the interactions of the magnetic Mn ions and clusters are studied using first-principles calculations. Curie temperatures are calculated using mean-field and Monte Carlo methods. It is found that joining substitutional Mn ions to clusters is energetically favorable and especially the structures of two to four Mn ions formed around a single N ion are most stable. These clusters are always found to have a ferromagnetic ground state, and ferromagnetic intercluster interactions are also present even at relatively long distances. For randomly distributed Mn impurities, high Curie temperatures are obtained at high Mn concentrations ͑above room temperature for x տ 0.14͒.

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“…35 the Mn-N bond length is found to be 2.07 Å, 0.12 Å longer than the Ga-N distance. Another experimental study gives the values of 1.98, .…”

Section: A Configurations Of Mn Clustersmentioning

confidence: 76%

Structural and magnetic properties of (Ga,Mn)N from first principles

2007

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“…The influence of the parameters of our process, like temperature, flow rate of nitriding agent and composition of the reaction mixture on the concentration of the magnetic ions in the samples was determined. Introduction of silicon into the reaction mixture caused an increase of concentration, from 4 to 8 at%, of manganese ions in the Ga(Mn,Si)N lattice compared to the Ga 1Àx Mn x N discussed earlier [13][14][15]17,18]. Such a high concentration is an unquestionable success.…”

Section: Discussionmentioning

confidence: 85%

Growth of bulk Ga(Mn,Si)N single crystals

Kamiński

Szyszko

Podsiadło

et al. 2006

Journal of Crystal Growth

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“…32,35 implying that the range of bond lengths is large for both ionic species in our films. Since these measurements were performed at low temperature, thermal effects on this disorder parameter are expected to be small.…”

Section: Resultsmentioning

confidence: 92%

Single phase nanocrystalline GaMnN thin films with high Mn content

Granville

Budde

Ruck

et al. 2006

Journal of Applied Physics

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Ga 1 − x Mn x N thin films with a Mn content as high as x=0.18 have been grown using ion-assisted deposition and a combination of Rutherford backscattering spectroscopy and nuclear reaction analysis was used to determine their composition. The structure of the films was determined from x-ray diffraction, transmission electron microscopy, and extended x-ray absorption fine structure (EXAFS). The films are comprised of nanocrystals of random stacked GaMnN and there is no evidence of Mn-rich secondary phases or clusters. EXAFS measurements at the Mn and Ga edge are almost identical to those at the Ga edge from Mn-free nanocrystalline GaN films, showing that the Mn occupies the Ga lattice sites, and simulated radial distribution functions of possible Mn-rich impurity phases bear no resemblance to the experimental data. The results indicate that these are the most heavily Mn-doped single phase GaN films studied to date.

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Probing local order in (Ga,Mn)N alloys by X-ray absorption spectroscopy

Cited by 22 publications

References 13 publications

Structural and magnetic properties of (Ga,Mn)N from first principles

Structural and magnetic properties of (Ga,Mn)N from first principles

Growth of bulk Ga(Mn,Si)N single crystals

Single phase nanocrystalline GaMnN thin films with high Mn content

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