A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. As the catalyst itself takes part in the reaction it may undergo a physical change. Hence, if catalysts take the form of nanoparticles, any physical feature of the nanoparticle interacting with the reacting molecules may […]
Chemistry • Condensed matter • Materials • Nanotechnology • Quantum physics
A quantum dot is a nanometric crystalline structure of semiconductor materials. In a quatum dot electrons are confined in a region of space, thus creating a well defined structure of energy levels that depends very much on the size and shape of the quantum dot. This structure resembles that of atoms, that is why sometimes […]
Condensed matter • Materials • Nanotechnology • Quantum physics
Imagine a military regiment in formation. That we will call symmetry. Now imagine the same regiment when it is dismissed by the commanding officer: at once the soldiers disperse and tend to form domains (groups) or pairs. Hence, we can say that the symmetry is spontaneously broken. Both superconductors and ferromagnets are examples of electron […]
Endohedral fullerenes, also called endofullerenes, are fullerenes that have additional atoms, ions, or clusters enclosed within their inner spheres. The first lanthanum C60 complex was synthesized in 1985 and called La@C60. The @ (at sign) in the name reflects the notion of a small molecule trapped inside a shell. The chemistry of endohedral fullerenes is […]
Common glass, used in windows or bottles, for example, is made by heating a mixture of calcium oxide (lime), sodium carbonate (soda), and silicon (IV) oxide (sand), resulting in a calcium silicate. This silicate is not a crystal but a solid in which atoms are positioned at random and have no long-range ordered pattern. These […]
Condensed matter • Materials • Nanotechnology • Quantum physics
Mobile phones and computers are currently responsible for up to 8% of the electricity use in the world. This figure has been doubling each past decade but nothing prevents it from skyrocketing in the future. Unless we find a way for boosting energy efficiency in information and communications technology, that is. An international team of […]
The ability to examine the vibrational spectra of liquids with nanometer spatial resolution will greatly expand the potential to study liquids and liquid interfaces. After all, modern technology, including many manufacturing processes, and science depend on understanding the detailed interactions at such nanoscopic interfaces. Actually, a better comprehension of the fundamental properties of the commonest […]
Condensed matter • Materials • Physics • Theoretical physics
Spacecraft components potentially exposed to different ionic projectiles in space, new materials used in new energy systems or healthy tissues exposed to cancer therapies are all instances where a full comprehension of how the energy of the incoming ions is dissipated by the matter in the target is of paramount importance. Besides, the dissipative processes […]
“What would happen if we could arrange the atoms one by one the way we want them?” Richard Feynman Fabrication of matter atom by atom remains a long-standing dream and ultimate goal of nanotechnology, following the famous challenge by Feynman 58 years ago. For 30 years, the atom-by-atom fabrication remained the province of visionary thinking […]
Imagine that we have a conductor or a semiconductor through which a current is flowing. Then we apply a strong transverse magnetic field. As a result, we can measure a potential difference at right angles to both the current and the field caused by the deflection of charge carriers by the field. This effect was […]