Ga Sublattice Defects in (Ga,Mn)As: Thermodynamical and Kinetic Trends

Tuomisto, Filip; Pennanen, K; Saarinen, K.; Sadowski, J.

doi:10.1103/physrevlett.93.055505

Cited by 34 publications

(30 citation statements)

References 25 publications

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“…This effect of metallic screening has been observed in the binary counterpart of ͑Zn, Mn͒GeAs 2 , p-type ͑Ga,Mn͒As, where the hole concentration was 10 20 cm −3 or greater. 23 In the present samples the hole concentration is in the mid-10 19 cm −3 range, and hence we find that the lack of temperature dependence in the positron data indicates that the observed vacancies are in the neutral charge state, giving further support to our interpretation of the higher lifetime component being due to As vacancies. As the samples are quite highly p-type and the formation enthalpy of negatively charged defects is high due to the Fermi energy being close to the valence band maximum and cation vacancies in compound semiconductors have a tendency to be acceptorlike ͑negatively charged͒, we note that it is rather natural to find neutrally charged donorlike As vacancies in ZnGeAs 2 .…”

Section: Discussionsupporting

confidence: 75%

Native vacancy defects in Zn1−x(Mn,Co)xGeAs2 studied with positron annihilation spectroscopy

Kilański

Zubiaga

Tuomisto

et al. 2009

Journal of Applied Physics

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We have studied vacancy defects in chalcopyrite semimagnetic semiconducting mixed Zn 1−x ͑Mn, Co͒ x GeAs 2 bulk crystals with alloy composition x varying between 0.052 to 0.182 using positron annihilation spectroscopy. We identified As vacancies, potentially complexed with the transition metal alloying elements, in all the studied samples, while no cation vacancy related defects were detected. The positron lifetimes for the bulk ZnGeAs 2 lattice and neutral As vacancy were determined to be B = 220-230 ps and As = 300Ϯ 10 ps, respectively. Our results also show that the p-type conductivity in the samples is not due to cation vacancy related acceptor centers. The As vacancies were found to be present at such low concentrations that they cannot be responsible for the compensation of the p-type conductivity or the reduction of mobility in the Zn 1−x ͑Mn, Co͒ x GeAs 2 samples.

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Section: Discussionsupporting

confidence: 75%

Native vacancy defects in Zn1−x(Mn,Co)xGeAs2 studied with positron annihilation spectroscopy

Kilański

Zubiaga

Tuomisto

et al. 2009

Journal of Applied Physics

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“…pattern for [11][12][13][14][15][16][17][18][19][20] zone axis fits well to the experimental image (see Fig. 3d).…”

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confidence: 77%

All-Wurtzite (In,Ga)As-(Ga,Mn)As Core–Shell Nanowires Grown by Molecular Beam Epitaxy

et al. 2014

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“…13,22 Our assumption that most of the Mn is located on Ga lattice sites rather than on interstitial sites therefore appears to be reasonable, indicating that the growth temperature used in this study is high enough to suppress the formation of point defects such as As antisites 8 and Ga vacancies. 9 Figure 7(b) shows a LA-APT reconstruction of the Mn distribution in the NW, which suggests that the Mn is distributed randomly within an examined volume of 40 Â 40 Â 270 nm 3 . The Mn therefore does not result in the formation of clusters or precipitates, even though the growth conditions used in this study can result in segregations of MnAs or As.…”

Section: Resultsmentioning

confidence: 99%

“…As a result of the very low solubility of Mn in GaAs, therefore, it is necessary to use non-equilibrium growth methods such as low-temperature molecular beam epitaxy (MBE), 2 below $300 C or Mn ion implantation into GaAs. 7 However, the samples grown by these methods contain usually a variety of point defects, such as As antisites, 8 Ga vacancies, 9 and Mn interstitials, 10 which degrade their semiconductive and magnetic properties.…”

Section: Introductionmentioning

confidence: 99%

Direct observation of doping incorporation pathways in self-catalytic GaMnAs nanowires

Kasama

Thuvander

Siusys

et al. 2015

Journal of Applied Physics

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Publication date: 2015 Document VersionPublisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Kasama, T., Thuvander, M., Siusys, A., Gontard, L. C., Kovács, A., Yazdi, S., ... Sadowski, J. (2015) Doping mechanisms of Mn in GaAs nanowires (NWs) that have been grown self-catalytically at 600 C by molecular beam epitaxy (MBE) are investigated using advanced electron microscopy techniques and atom probe tomography. Mn is found to be incorporated primarily in the form of non-magnetic tetragonal Ga 0.82 Mn 0.18 nanocrystals in Ga catalyst droplets at the ends of the NWs, while trace amounts of Mn (22 6 4 at. ppm) are also distributed randomly in the NW bodies without forming clusters or precipitates. The nanocrystals are likely to form after switching off the reaction in the MBE chamber, since they are partially embedded in neck regions of the NWs. The Ga 0.82 Mn 0.18 nanocrystals and the low Mn concentration in the NW bodies are insufficient to induce a ferromagnetic phase transition, suggesting that it is difficult to have high Mn contents in GaAs even in 1-D NW growth via the vapor-liquid-solid process. V C 2015 AIP Publishing LLC.

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Ga Sublattice Defects in (Ga,Mn)As: Thermodynamical and Kinetic Trends

Cited by 34 publications

References 25 publications

Native vacancy defects in Zn1−x(Mn,Co)xGeAs2 studied with positron annihilation spectroscopy

Native vacancy defects in Zn1−x(Mn,Co)xGeAs2 studied with positron annihilation spectroscopy

All-Wurtzite (In,Ga)As-(Ga,Mn)As Core–Shell Nanowires Grown by Molecular Beam Epitaxy

Direct observation of doping incorporation pathways in self-catalytic GaMnAs nanowires

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