scholarly journals Fullerenes

1993 ◽  
Vol 8 (8) ◽  
pp. 2054-2097 ◽  
Author(s):  
M.S. Dresselhaus ◽  
G. Dresselhaus ◽  
P.C. Eklund
Keyword(s):  
Alkali Metal ◽  
Electronic Band Structure ◽  
Molecular Solids ◽  
Structure And Properties ◽  
Electronic Band ◽  
Structure And Property ◽  
Doped Fullerenes ◽  
Potential Applications ◽  
Metal Doped ◽  
Lattice Modes

A review of the structure and properties of fullerenes is presented. Emphasis is given to their behavior as molecular solids. The structure and property modifications produced by alkali-metal doping are summarized, including modification to the electronic structure, lattice modes, transport, and optical properties. Particular emphasis is given to the alkali-metal-doped fullerenes because of their importance as superconductors. A review of the structure and properties of fullerene-based graphene tubules is also given, including a model for their one-dimensional electronic band structure. Potential applications for fullerene-based materials are suggested.

Electron-Phonon Coupling in Superconducting Alkali-Metal Doped Fullerenes

1992 ◽  
Vol 270 ◽  
Author(s):  
R.A. Jishi ◽  
M.S. Dresseliiaus
Keyword(s):  
Experimental Data ◽  
Alkali Metal ◽  
Phonon Mode ◽  
Coupling Parameter ◽  
Tight Binding ◽  
Superconducting Transition ◽  
Phonon Coupling ◽  
Doped Fullerenes ◽  
Electron Phonon Coupling ◽  
Metal Doped

ABSTRACTThe dimensionless electron-phonon coupling parameter in alkali metal-doped fullerenes isevaluated in a model whereby the electrons are treated within a tight binding formalism.The phonon mode frequencies and eigenvectors are obtained from a lattice dynamical modelwhich accurately fits all available experimental data on these modes. It is shown that the electrormphonon interaction can account for the relatively high values of the superconducting transition temperatures in alkali-metal fullerenes.

Optical evidence of metal-insulator phase transition in alkali metal doped fullerenes

1997 ◽  
Vol 86 (1-3) ◽  
pp. 2343-2344
Author(s):  
F. Bommeli ◽  
L. Degiorgi ◽  
P. Wachter ◽  
L. Forro
Keyword(s):  
Phase Transition ◽  
Alkali Metal ◽  
Metal Insulator ◽  
Doped Fullerenes ◽  
Insulator Phase Transition ◽  
Metal Doped ◽  
Optical Evidence

ELECTRONIC PRINCIPLES OF SOME TRENDS IN PROPERTIES OF METALLIC HYDRIDES

2010 ◽  
Vol 24 (06n07) ◽  
pp. 703-710 ◽  
Author(s):  
NENAD IVANOVIĆ ◽  
NIKOLA NOVAKOVIĆ ◽  
DANIELE COLOGNESI ◽  
IVANA RADISAVLJEVIĆ ◽  
STANKO OSTOJIĆ
Keyword(s):  
Physical Properties ◽  
Alkaline Earth ◽  
Tight Binding ◽  
Experimental Studies ◽  
Valuable Insight ◽  
First Principle ◽  
Structure And Properties ◽  
Potential Applications ◽  
Bader Analysis ◽  
Metal Doped

Due to their extensive present, important and versatile potential applications, metal hydrides (MH) are among the most investigated solid-state systems. Theoretical, numerical and experimental studies have provided a considerable knowledge about their structure and properties, but in spite of that, the basic electronic principles of various interactions present in MH have not yet been completely resolved. Even in the simplest MH, i.e. alkali hydrides (Alk-H), some trends in physical properties, and especially their deviations, are not well understood. Similar doubts exist for the alkaline-earth hydride (AlkE-H) series, and are even more pronounced for complex systems, like transition metal-doped AlkE-H, alanates and borohydrides. This work is an attempt of explaining some trends in the physical properties of Alk-H and AlkE-H, employing the Bader analysis of the charge distribution topology evaluated by first-principle all-electron calculations. These results are related to some variables commonly used in the explanation of experimental and calculated results, and are also accompanied by simple tight-binding estimations. Such an approach provides a valuable insight in the characteristics of M-H and H-H interactions in these hydrides, and their possible changes along with external parameters, like temperature, pressure, defect or impurity introduction. The knowledge of these basic interactions and processes taking place in simple MH are essential for the design and optimisation of complex MH-systems interesting for practical hydrogen storage applications.

scholarly journals A Review of Self-Seeded Germanium Nanowires: Synthesis, Growth Mechanisms and Potential Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2002
Author(s):  
Adrià Garcia-Gil ◽  
Subhajit Biswas ◽  
Justin D. Holmes
Keyword(s):  
Electronic Band Structure ◽  
Phonon Transport ◽  
Nanowire Growth ◽  
Seeded Growth ◽  
Electronic Band ◽  
Germanium Nanowires ◽  
Catalyst Metal ◽  
Potential Applications ◽  
Growth Method ◽  
On Chip

Ge nanowires are playing a big role in the development of new functional microelectronic modules, such as gate-all-around field-effect transistor devices, on-chip lasers and photodetectors. The widely used three-phase bottom-up growth method utilising a foreign catalyst metal or metalloid is by far the most popular for Ge nanowire growth. However, to fully utilise the potential of Ge nanowires, it is important to explore and understand alternative and functional growth paradigms such as self-seeded nanowire growth, where nanowire growth is usually directed by the in situ-formed catalysts of the growth material, i.e., Ge in this case. Additionally, it is important to understand how the self-seeded nanowires can benefit the device application of nanomaterials as the additional metal seeding can influence electron and phonon transport, and the electronic band structure in the nanomaterials. Here, we review recent advances in the growth and application of self-seeded Ge and Ge-based binary alloy (GeSn) nanowires. Different fabrication methods for growing self-seeded Ge nanowires are delineated and correlated with metal seeded growth. This review also highlights the requirement and advantage of self-seeded growth approach for Ge nanomaterials in the potential applications in energy storage and nanoelectronic devices.

Isotope Effect and Superconductivity in Metal-Doped C60

Science ◽  
1993 ◽  
Vol 259 (5095) ◽  
pp. 655-658 ◽  
Author(s):  
Chia-Chun Chen ◽  
Charles M. Lieber
Keyword(s):  
Transition Temperature ◽  
Alkali Metal ◽  
Isotope Shift ◽  
Isotopic Substitution ◽  
Mass Scaling ◽  
Doped Fullerenes ◽  
Simple Mass ◽  
Mechanism Of Superconductivity ◽  
Metal Doped

The mechanism of superconductivity in alkali metal-doped fullerenes remains a fascinating and controversial issue. One powerful probe of this mechanism involves the determination of the shift in transition temperature (δTc) upon isotopic substitution. A series of isotopically substituted Rb3C60 superconductors, where C60 corresponds to 13C60, (13C60)0.5(12C60)0.5, or (13C0.5512C0.45)60, was investigated. The δTc determined for Rb313C60, 0.7 ± 0.1 K, provides an unambiguous value for the isotope shift in fully substituted fullerene superconductors. The δTc determined for Rb3 (13C0.5512C0.45)60, 0.5 K, is also consistent with simple mass scaling of the Rb313C60 result. However, an intermolecular effect not accounted for in existing theories is demonstrated by the unexpectedly large δTc, 0.9 K, that was observed for the Rb3(13C60)0.5(12C60)0.5 materials. These results are used to critically assess proposed mechanisms of fullerene superconductivity.

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