Here is a new form of water, solid and liquid at the same time
A team of US researchers managed to get superionic water in the lab. Solid and liquid at the same time, it exists but not on Earth and could lead to developments in new material technologies
Can water be solid and liquid at the same time? It would seem absurd, yet a team of researchers from the Lawrence Livermore National Laboratory and the University of California-Berkeley managed to obtain a new form of water, subjecting it to extreme temperature and pressure conditions similar to those that would be found on Neptune or Uranus. The effort of the Americans, recently published in Nature Physics, confirms the Italian research carried out almost 20 years ago on the so-called Supraonic Water.
The strange fluid is really water: two hydrogen atoms bind to an oxygen atom to make a molecule. But what makes superionic water so exceptional is the structure that the molecules take on, i. e. a rigid grid of oxygen atoms in which the positively charged hydrogen nuclei (ions) move.
It's as if ice was partially melted,"explained Raymond Jeanloz, professor of planetary and terrestrial sciences at the University of California-Berkeley and research author at the New York Times.
Such a form of water does not exist on Earth, experts say, but it may be somewhere in our Solar System - for example on Uranus and Neptune. A similar organisation of molecules. In fact, it is only possible under extreme temperature and pressure conditions: while heat dissolves the bonds between oxygen and hydrogen atoms, high pressure maintains the oxygen atoms - which are larger and heavier than hydrogen ones - stacked, forming a fixed crystalline structure (the solid component), while hydrogen ions are free to flow through the lattice (and this is the liquid component).
Researchers have replicated these conditions by squeezing water molecules between two diamonds, subjecting it to a pressure 25 thousand times greater than that experienced on the surface of the Earth. They have thus obtained a stadium that physicists call ice VII, 60% denser than ordinary water and solid at room temperature. At a later stage, this ice was bombed with a laser pulse that for 10-20 billionths of a second caused shockwaves in matter, heating it to thousands of degrees at a pressure one million times greater than that of the earth's atmosphere.
This is the first time scientists have obtained superior water in the laboratory, but alternative forms of water have been studied for over 20 years. It was in 1999, for example, the publication of a research conducted by the International School of Advanced Higher Education (Sissa) and the International Centre for Theoretical Physics (Ictp) in Trieste, whose simulations of water surpassed today's results.
Superior water is a current conductor, like metals but with a substantial difference. While in metals the current is given by the flow of electrons, in superionic water it is the positive ions, the hydrogen that conduct.
Having obtained the superior water, as well as being able to provide information on the strange magnetic fields of the ice giants Uranus and Neptune, opens the way to new frontiers in the field of research on new materials.