Limits...
Coherent magnetic semiconductor nanodot arrays.

Wang Y, Xiu F, Wang Y, Zou J, Beyermann WP, Zhou Y, Wang KL - Nanoscale Res Lett (2011)

Bottom Line: In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors.Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility.The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, St Lucia Campus, Brisbane QLD 4072, Australia. y.wang4@uq.edu.au.

ABSTRACT
In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors. Up to now, lack of reliable methods to obtain high-quality MnGe nanostructures with a desired shape and a good controllability has been a barrier to make these materials practically applicable for spintronic devices. Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility. Magnetotransport experiments reveal that the nanodot arrays possess giant magneto-resistance associated with geometrical effects. The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation.

No MeSH data available.


Related in: MedlinePlus

Schematic drawings of MnGe nanodot arrays. (a) Controlled growth approach of inter-stacked Ge (green) and MnGe (bright) layers with a sequence from the bottom: substrate (Ge or GaAs)/Ge buffer layer/four (MnGe/Ge) layers. (b) MnGe nanodot arrays.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211181&req=5

Figure 1: Schematic drawings of MnGe nanodot arrays. (a) Controlled growth approach of inter-stacked Ge (green) and MnGe (bright) layers with a sequence from the bottom: substrate (Ge or GaAs)/Ge buffer layer/four (MnGe/Ge) layers. (b) MnGe nanodot arrays.

Mentions: A "superlattice" growth approach was carried out by alternating the growth of Mn-doped Ge and undoped Ge thin layers with a Perkin Elmer molecular beam epitaxy. High-purity Ge (99.9999%) and Mn (99.99%) sources were evaporated by conventional high-temperature effusion cells. During the growth, a Ge growth rate of 0.2 Å/s with an adjustable Mn flux as the dopant source was used. The designated structure is schematically shown in Figure 1 and Figure S1 in Additional file 1. First of all, a high-quality single-crystalline Ge buffer layer was deposited at 250°C with a thickness of ca. 60 nm. The surface of the buffer layer was monitored by the reflection high-energy electron diffraction (RHEED) technique and found to be atomic flat evidenced by the streaky RHEED patterns. The growth temperature was then decreased to 70°C for the subsequent "superlattice" growth. Ten periods of Ge and MnGe layers were grown for each case. Different growth parameters (including nominal thicknesses of Ge and MnGe layers, the Mn concentrations and the growth temperatures) were employed in order to obtain MnGe nanodot arrays. It is worthwhile noting that the quality of the buffer layer is crucial for the subsequent low-temperature growth of the MnGe film.


Coherent magnetic semiconductor nanodot arrays.

Wang Y, Xiu F, Wang Y, Zou J, Beyermann WP, Zhou Y, Wang KL - Nanoscale Res Lett (2011)

Schematic drawings of MnGe nanodot arrays. (a) Controlled growth approach of inter-stacked Ge (green) and MnGe (bright) layers with a sequence from the bottom: substrate (Ge or GaAs)/Ge buffer layer/four (MnGe/Ge) layers. (b) MnGe nanodot arrays.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211181&req=5

Figure 1: Schematic drawings of MnGe nanodot arrays. (a) Controlled growth approach of inter-stacked Ge (green) and MnGe (bright) layers with a sequence from the bottom: substrate (Ge or GaAs)/Ge buffer layer/four (MnGe/Ge) layers. (b) MnGe nanodot arrays.
Mentions: A "superlattice" growth approach was carried out by alternating the growth of Mn-doped Ge and undoped Ge thin layers with a Perkin Elmer molecular beam epitaxy. High-purity Ge (99.9999%) and Mn (99.99%) sources were evaporated by conventional high-temperature effusion cells. During the growth, a Ge growth rate of 0.2 Å/s with an adjustable Mn flux as the dopant source was used. The designated structure is schematically shown in Figure 1 and Figure S1 in Additional file 1. First of all, a high-quality single-crystalline Ge buffer layer was deposited at 250°C with a thickness of ca. 60 nm. The surface of the buffer layer was monitored by the reflection high-energy electron diffraction (RHEED) technique and found to be atomic flat evidenced by the streaky RHEED patterns. The growth temperature was then decreased to 70°C for the subsequent "superlattice" growth. Ten periods of Ge and MnGe layers were grown for each case. Different growth parameters (including nominal thicknesses of Ge and MnGe layers, the Mn concentrations and the growth temperatures) were employed in order to obtain MnGe nanodot arrays. It is worthwhile noting that the quality of the buffer layer is crucial for the subsequent low-temperature growth of the MnGe film.

Bottom Line: In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors.Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility.The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, St Lucia Campus, Brisbane QLD 4072, Australia. y.wang4@uq.edu.au.

ABSTRACT
In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors. Up to now, lack of reliable methods to obtain high-quality MnGe nanostructures with a desired shape and a good controllability has been a barrier to make these materials practically applicable for spintronic devices. Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility. Magnetotransport experiments reveal that the nanodot arrays possess giant magneto-resistance associated with geometrical effects. The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation.

No MeSH data available.


Related in: MedlinePlus