Passivation of Mn acceptors in GaMnAs

Brandt, Martin S.; Goennenwein, Sebastian T. B.; Wassner, Thomas A.; Kohl, Florian J.; Lehner, Angelika; Huebl, Hans; Graf, T.; Stutzmann, M.; Koeder, A.; Schoch, W.; Waag, A.

doi:10.1063/1.1690470

Cited by 36 publications

(40 citation statements)

References 23 publications

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“…In this complex, H is located close to the center of the As-Mn bond, which corresponds to a different geometry from that suggested by the IR measurements. [3] The estimated As-H vibrational frequency and the calculated magnetization of the Mn atom in the complex agree well with the experiment. Moreover, an investigation of the defect level induced by the Mn atom in the energy gap shows that such a level is removed from the gap when the As-H(-Mn) complex is formed.…”

Section: Introductionsupporting

confidence: 73%

“…The values given in Tables I and II show that the results achieved for the most stable complex (ab-Mn) do not agree with the experimental fi ndings. In particular, the theoretical results do not agree with a measured vibrational frequency of 2143 cm −1 and a total magnetization of 5 µ B , [3,5] see Table II. On the other hand, the H complexes that could agree with the experiment, e.g., the linear bc-As(Mn), are much higher in energy than the ab-Mn one.…”

Section: P Giannozzi Et Almentioning

confidence: 39%

“…Infrared measurements of hydrogenated (deuterated) Mn x Ga 1−x As show As-H (As-D) local vibrational modes characteristic of the complexes formed by hydrogen with group II acceptors in GaAs. [3,4] Magnetization measurements show that as-grown Mn x Ga 1−x As fi lms are ferromagnetic whereas they are found to be paramagnetic after hydrogenation. [5] Moreover, electronic transport measurements indicate that the density of the free holes is signifi cantly reduced by hydrogenation.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Theory of hydrogen complexes in Mn xGa1-xAs dilute magnetic semiconductors

Giannozzi¹,

Filippone²,

Bonapasta³

2006

Braz. J. Phys.

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Atomic hydrogen diffuses in semiconductor lattices and binds to impurities by forming complexes that can lead to a full neutralization of the impurity effects. In the present paper, the structural, vibrational, electronic and magnetic properties of complexes formed by H in the Mn x Ga 1−x As (x=0.03) dilute magnetic semiconductor have been investigated by using fi rst-principles DFT-LSD and LDA+U theoretical methods. The results account for recent experimental fi ndings showing a H passivation of the electronic and magnetic properties of Mn in GaAs. Moreover, they show that electron correlation has crucial effects on the properties of H-Mn complexes.

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Section: Introductionsupporting

confidence: 73%

Section: P Giannozzi Et Almentioning

confidence: 39%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Theory of hydrogen complexes in Mn xGa1-xAs dilute magnetic semiconductors

Giannozzi¹,

Filippone²,

Bonapasta³

2006

Braz. J. Phys.

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“…Hydrogen passivates Mn in Ga 1-x Mn x As by occupying a bond-center location between the Mn and its nearest neighbouring anion; the Mn-H complex is electrically and magnetically inactive [3,5,6]. In Fig.…”

Section: Hydrogen Passivation Patterningmentioning

confidence: 97%

2D‐patterned ferromagnetic III‐Mn‐V semiconductors for planar spintronics

Farshchi

Chopdekar

Suzuki

et al. 2007

Phys. Status Solidi (c)

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We demonstrate planar patterning techniques to produce isolated regions of ferromagnetic Ga 1-x Mn x As embedded in a GaAs host. One technique consists of ion-implantation through lithographically defined resist, followed by pulsed-laser melting. Planar Hall-bar structures of Ga 1-x Mn x As formed by this process show a large anomalous Hall signal along with negative magnetoresistance associated with the wellknown hole-mediated ferromagnetic phase. In another technique patterning is achieved by selective hydrogenation of Ga 1-x Mn x As, rendering exposed regions electrically insulating and magnetically inactive. The planar nature of these Hall-bars allows for tuning the ferromagnetism by the integration of lateral gates to modulate the exchange-mediating hole population in the Ga 1-x Mn x As region, hence creating junction-FET functionality.

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“…Hydrogenation of Ga 1-x Mn x As has the well-known effect of passivating Mn acceptors [5][6][7][8]. Hydrogen forms a complex with Mn and a neighboring As atom in which Mn is no longer an electrically active acceptor and hence ceases to provide a hole to mediate inter-Mn ferromagnetic exchange in the film.…”

mentioning

confidence: 99%

Hydrogen patterning of Ga1−xMnxAs for planar spintronics

Farshchi

Ashby

Hwang

et al. 2007

Physica B: Condensed Matter

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We demonstrate two patterning techniques based on hydrogen passivation of Ga 1-x Mn x As to produce isolated ferromagnetically active regions embedded uniformly in a paramagnetic, insulating host. The first method consists of selective hydrogenation of Ga 1-x Mn x As by lithographic masking. Magnetotransport measurements of Hall-bars made in this manner display the characteristic properties of the hole-mediated ferromagnetic phase, which result from good pattern isolation. Arrays of Ga 1-x Mn x As dots as small as 250 nm across have been realized by this process. The second process consists of blanket hydrogenation of Ga 1-x Mn x As followed by local reactivation using confined low-power pulsed-laser annealing. Conductance imaging reveals local electrical reactivation of micrometer-sized regions that accompanies the restoration of ferromagnetism. The spatial resolution achievable with this method can potentially reach <100 nm by employing near-field laser processing. The high spatial resolution attainable by hydrogenation patterning enables the development of systems with novel functionalities such as lateral spin-injection as well as the exploration of magnetization dynamics in individual and coupled structures made from this novel class of semiconductors.

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Passivation of Mn acceptors in GaMnAs

Cited by 36 publications

References 23 publications

Theory of hydrogen complexes in Mn xGa1-xAs dilute magnetic semiconductors

Theory of hydrogen complexes in Mn xGa1-xAs dilute magnetic semiconductors

2D‐patterned ferromagnetic III‐Mn‐V semiconductors for planar spintronics

Hydrogen patterning of Ga1−xMnxAs for planar spintronics

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