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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

Transmission electron microscopy (TEM), scanning TEM and energy dispersive X-ray spectroscopy (EDS) results of the multilayer MnGe nanodots. (a) A typical low-magnification plane-view bright-field TEM image showing MnGe nanodots (dark spots). (b) A plane-view low-angle dark-field STEM image showing the MnGe nanodots (white spots). (c) A low-magnification cross-sectional bright-field TEM image showing the obtained MnGe nanodot array in a large area. (d) A higher-magnification cross-sectional TEM image and (e) a cross-section STEM image, both showing the MnGe nanodot arrays. (f) A EDS profile showing the Mn and Ge peaks. (g, h) EDS line-scan profiles of the marked line in (b) and (e) using Mn K peak, respectively, confirming nanodots being Mn rich. All TEM images are taken from the same sample.
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Figure 2: Transmission electron microscopy (TEM), scanning TEM and energy dispersive X-ray spectroscopy (EDS) results of the multilayer MnGe nanodots. (a) A typical low-magnification plane-view bright-field TEM image showing MnGe nanodots (dark spots). (b) A plane-view low-angle dark-field STEM image showing the MnGe nanodots (white spots). (c) A low-magnification cross-sectional bright-field TEM image showing the obtained MnGe nanodot array in a large area. (d) A higher-magnification cross-sectional TEM image and (e) a cross-section STEM image, both showing the MnGe nanodot arrays. (f) A EDS profile showing the Mn and Ge peaks. (g, h) EDS line-scan profiles of the marked line in (b) and (e) using Mn K peak, respectively, confirming nanodots being Mn rich. All TEM images are taken from the same sample.

Mentions: The high-resolution transmission electron microscopy (TEM) and scanning TEM (STEM) experiments were performed on a FEI Tecnai F20 (S)TEM operating at 200 kV. The digital images were recorded by a Gatan® 2k × 2k CCD camera. All the TEM and STEM images were taken in standard conditions. However, it should be noted that the MnGe nanodots appear dark contrast in the bright-field TEM mode (Figure 2a, c, d) which is different from the case in the low-angle dark-field STEM mode (Figure 2b, e) where the MnGe show white contrast due to different imaging systems.


Coherent magnetic semiconductor nanodot arrays.

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

Transmission electron microscopy (TEM), scanning TEM and energy dispersive X-ray spectroscopy (EDS) results of the multilayer MnGe nanodots. (a) A typical low-magnification plane-view bright-field TEM image showing MnGe nanodots (dark spots). (b) A plane-view low-angle dark-field STEM image showing the MnGe nanodots (white spots). (c) A low-magnification cross-sectional bright-field TEM image showing the obtained MnGe nanodot array in a large area. (d) A higher-magnification cross-sectional TEM image and (e) a cross-section STEM image, both showing the MnGe nanodot arrays. (f) A EDS profile showing the Mn and Ge peaks. (g, h) EDS line-scan profiles of the marked line in (b) and (e) using Mn K peak, respectively, confirming nanodots being Mn rich. All TEM images are taken from the same sample.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Transmission electron microscopy (TEM), scanning TEM and energy dispersive X-ray spectroscopy (EDS) results of the multilayer MnGe nanodots. (a) A typical low-magnification plane-view bright-field TEM image showing MnGe nanodots (dark spots). (b) A plane-view low-angle dark-field STEM image showing the MnGe nanodots (white spots). (c) A low-magnification cross-sectional bright-field TEM image showing the obtained MnGe nanodot array in a large area. (d) A higher-magnification cross-sectional TEM image and (e) a cross-section STEM image, both showing the MnGe nanodot arrays. (f) A EDS profile showing the Mn and Ge peaks. (g, h) EDS line-scan profiles of the marked line in (b) and (e) using Mn K peak, respectively, confirming nanodots being Mn rich. All TEM images are taken from the same sample.
Mentions: The high-resolution transmission electron microscopy (TEM) and scanning TEM (STEM) experiments were performed on a FEI Tecnai F20 (S)TEM operating at 200 kV. The digital images were recorded by a Gatan® 2k × 2k CCD camera. All the TEM and STEM images were taken in standard conditions. However, it should be noted that the MnGe nanodots appear dark contrast in the bright-field TEM mode (Figure 2a, c, d) which is different from the case in the low-angle dark-field STEM mode (Figure 2b, e) where the MnGe show white contrast due to different imaging systems.

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