From Germanium Nanowires to Germanium−Silicon Oxide Nanotubes: Influence of Germanium Tetraiodide Precursor

In several nanotechnological applications the dewetting process is crucial. Although not all phenomena of dewetting are fully understood yet, especially with regard to metallic fluids, it is clear that the formation of nanoparticles, -droplets, and -clusters and their movement is strongly linked to their wetting behaviour. For this reason, the thermodynamic stability of thin metal layers (0.1 – 100 nm) with respect to its free energy is examined here. The decisive factor for the theoretical consideration is the interfacial energy. In order to achieve a better understanding of the interface interactions, three different models for the estimation of this energy are presented: i. fully theoretical, ii. empirical and iii. semi-empirical. The formation of nanometre-sized gold particles on silicon and silicon oxide is investigated in detail, elucidating the strengths and weaknesses of the three models, comparing the different substrates, and verifying the possibility of further processing of the gained particles as nanocatalysts. The importance of a persistent thin communication wetting layer between the particles and its effects on their size and number also becomes clear. In particular, the intrinsic reduction of the Laplace pressure of the system by material re-evaporation and Ostwald ripening is considered to describe the theoretically predicted and experimentally found effects. Thus dewetting phenomena of thin metal layers can be well-directed used for the manufacturing of nanostructured devices. From this viewpoint, the behaviour of gold droplets as catalysts to grow germanium nanowires on different substrates is described.

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On the energy and time resolution measurements of bismuth germanium silicon oxide (BGSO) crystal grown by Czochralski technique

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2004.09.052 ◽

2005 ◽

Vol 273 (3-4) ◽

pp. 481-488 ◽

Cited By ~ 7

Author(s):

V. Vaithianathan ◽

A. Claude ◽

P. Santhanaraghavan ◽

P. Ramasamy

Keyword(s):

Time Resolution ◽

Silicon Oxide ◽

Czochralski Technique ◽

Germanium Silicon

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Czochralski growth of bismuth germanium silicon oxide (BGSO) single crystal and its characterization

Journal of Crystal Growth ◽

10.1016/s0022-0248(01)01725-0 ◽

2002 ◽

Vol 235 (1-4) ◽

pp. 212-216 ◽

Cited By ~ 9

Author(s):

V. Vaithianathan ◽

S. Kumaragurubaran ◽

N. Senguttuvan ◽

P. Santhanaraghavan ◽

M. Ishii ◽

...

Keyword(s):

Single Crystal ◽

Silicon Oxide ◽

Czochralski Growth ◽

Germanium Silicon

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Crystal structure of manganese gallium germanium silicon oxide (garnet type), Mn3(Ga2–yMny)(Ge3–zSiz)O12 (y = 0.6, z = 0.14; y = 0.44, z = 0), and of manganese gallium germanium silicon oxide (braunite type), Mn(Mn6–yGay)(Si1–zGez)O12 (y = 0.7, z = 0.4)

Zeitschrift für Kristallographie - New Crystal Structures ◽

10.1524/ncrs.2003.218.4.373 ◽

2003 ◽

Vol 218 (4) ◽

pp. 373-375

Author(s):

R. Wartchow ◽

L. Müller ◽

M. Binnewies

Keyword(s):

Crystal Structure ◽

Silicon Oxide ◽

Germanium Silicon

Abstract Ga1.4Ge2.86Mn3.6O12Si0.14 (1), cubic, Ia3̅d (No. 230), a = 12.043(3) Å, V = 1746.6 Å3, Z = 8, Rgt(F) = 0.028, wRref(F2) = 0.062, T = 300 K. Ga1.56Ge3Mn3.44O12 (2), cubic, Ia3̅d (No. 230), a = 12.049(3) Å, V = 1749.3 Å3, Z = 8, Rgt(F) = 0.023, wRref(F2) = 0.052, T = 300 K. Ga0.7Ge0.4Mn6.3O12Si0.6 (3), tetragonal, I41/acd (No. 142), a = 9.464(4) Å, c = 18.78(3) Å, V = 1682.1 Å3, Z = 8, Rgt(F) = 0.023, wRref(F2) = 0.053, T = 300 K.

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Structural Stability of Amorphous Semiconductor Superlattices

MRS Proceedings ◽

10.1557/proc-160-547 ◽

1989 ◽

Vol 160 ◽

Cited By ~ 1

Author(s):

P. D. Persans ◽

A. F. Ruppert ◽

B. Abeles ◽

Y. J. Wu ◽

V. Pantojas ◽

...

Keyword(s):

Silicon Oxide ◽

Amorphous Semiconductor ◽

X Ray ◽

Sublayer Thickness ◽

20 Nm ◽

Germanium Silicon ◽

Hydrogenated Amorphous ◽

Hydrogenated Amorphous Germanium ◽

Thermal Stability Of ◽

Extract Information

AbstractWe report recent results of studies of the structure and thermal stability of periodic multilayers based on hydrogenated amorphous silicon, hydrogenated amorphous germanium, silicon nitride and silicon oxide. By varying the sublayer thickness from 1 nm to 20 nm it is possible to extract information on the range and magnitude of relaxation and interdiffusion in these metastable materials. It is also possible to gain information on the influence of interfaces on crystallization and relaxation. The principal techniques discussed here are Raman scattering, optical absorption and high resolution x-ray reflectivity.

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Raman study of gaseous bubble inclusions in bismuth germanate and bismuth germanium silicon oxide single crystals

Journal of Materials Research ◽

10.1557/jmr.2003.0105 ◽

2003 ◽

Vol 18 (4) ◽

pp. 762-767 ◽

Cited By ~ 2

Author(s):

V. Vaithianathan ◽

R. Kesavamoorthy ◽

C. V. Kannan ◽

P. Santhanaraghavan ◽

P. Ramasamy

Keyword(s):

Silicon Oxide ◽

Vibrational Mode ◽

Pressure Coefficient ◽

Blue Shift ◽

Gas Pressure ◽

Bismuth Germanate ◽

Raman Modes ◽

Gaseous Bubble ◽

Raman Study ◽

Germanium Silicon

Gaseous bubble inclusions in bismuth germanate (BGO) and bismuth germanium silicon oxide (BGSO) crystals were studied by means of Raman spectroscopy at room temperature. Their Raman spectra in the range from 60 to 70 cm−1 showed three peaks for the rotational Raman modes of O2 and N2. Vibrational Raman modes of O2 and N2 were also recorded for BGO and BGSO crystals. It was found that all the rotational and vibrational modes were blue shifted from those of free molecules due to the hydrostatic pressure in the bubbles. Internal pressure in the bubbles was estimated from the rotational and vibrational Raman mode frequencies. O2 gas pressure in the bubble was estimated as 140 GPa, and N2 gas pressure, as 31 GPa. The pressure coefficient of the vibrational mode frequency of O2 (0.368 cm−1/GPa for O2 vibrational mode of 1580 cm−1) and N2 (0.322 cm−1/GPa for N2 vibrational mode of 2331 cm−1) was also obtained from the blue shift and the calculated bubble pressure.

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Analysis of catalyst surface wetting: the early stage of epitaxial germanium nanowire growth

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.11.121 ◽

2020 ◽

Vol 11 ◽

pp. 1371-1380 ◽

Cited By ~ 1

Author(s):

Owen C Ernst ◽

Felix Lange ◽

David Uebel ◽

Thomas Teubner ◽

Torsten Boeck

Keyword(s):

Interfacial Energy ◽

Silicon Oxide ◽

Ostwald Ripening ◽

Early Stage ◽

Point Of View ◽

Thin Metal ◽

Surface Wetting ◽

Germanium Nanowires ◽

Semi Empirical ◽

Metal Layers

The dewetting process is crucial for several applications in nanotechnology. Even though not all dewetting phenomena are fully understood yet, especially regarding metallic fluids, it is clear that the formation of nanometre-sized particles, droplets, and clusters as well as their movement are strongly linked to their wetting behaviour. For this reason, the thermodynamic stability of thin metal layers (0.1–100 nm) with respect to their free energy is examined here. The decisive factor for the theoretical considerations is the interfacial energy. In order to achieve a better understanding of the interfacial interactions, three different models for estimating the interfacial energy are presented here: (i) fully theoretical, (ii) empirical, and (iii) semi-empirical models. The formation of nanometre-sized gold particles on silicon and silicon oxide substrates is investigated in detail. In addition, the strengths and weaknesses of the three models are elucidated, the different substrates used are compared, and the possibility to further process the obtained particles as nanocatalysts is verified. The importance of a persistent thin communication wetting layer between the particles and its effects on particle size and number is also clarified here. In particular, the intrinsic reduction of the Laplace pressure of the system due to material re-evaporation and Ostwald ripening describes the theoretically predicted and experimentally obtained results. Thus, dewetting phenomena of thin metal layers can be used to manufacture nanostructured devices. From this point of view, the application of gold droplets as catalysts to grow germanium nanowires on different substrates is described.

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