Crystals and glasses have opposite heat driving properties, which play a fundamental role in a variety of technologies. These range from miniaturization and the efficiency of electronic devices to the recovery systems of the waste state, as well as the useful life of thermal shields for aerospace applications.
The problem of optimizing the performance and durability of the materials used in these different applications is essential to fundamentally understand how its chemical composition and atomic structure (for example, crystalline, glassy, nanostructured) determine their ability to heat. Michele Simoncelli, assistant professor of applied physics and mathematics applied in Columbia Engineering, addresses this problem of the first principles, that is, in the words of Aristotle, in terms of “The first base of which a thing is known“-As from the fundamental equations of quantum mechanics and the use of automatic learning techniques to solve them with quantitative precision.
In Research Published on July 11 in the Proceedings of the National Academy of Sciences, Simoncelli and His Collaborators Nicola Marzari From The Swiss Federal Technology Institute of Lausanne and Francesco Mauri From Sapienza University of Rome Predicted The Existence of A Material With Hybrid Crystal-Glass Properties, and A Team of Experimentalists LED by Etienne Balan, Daniele Fournier, and Massimilian Marangolo of the University of Sorbonne in Paris confirmed it with measurements.
The first of its kind, this material was discovered in meteorites and has also been identified on Mars. The fundamental physics that promotes this behavior could advance in our understanding and design of materials that handle heat under extreme temperature differences, and, in general, provide information on the thermal history of the planets.
A unified theory of thermal transport in atomically ordered crystals and messy glasses
The thermal conduction depends on whether a material is crystalline, with an orderly network of atoms, or glassy, with a messy amorphous structure, which influences how heat flows at quantum level of speaking quietly, thermal conduction in the crystals generally decreases with the increase in temperature, while in the glasses it increases when heating.
In 2019, Simoncelli, Nicola Marzari and Francesco Mauri obtained a single equation that captures the opposite thermal conductivity trends observed in crystals and glasses, and, most importantly, it also describes the intermediate behavior of defective or partially disorderly materials, such as those used in the recovery of heat themes of the thermal, and the solar cells of the heats.
Using this equation, they investigated the relationship between atomic structure and thermal conductivity in materials of silicon dioxide, one of the main components of the sand. They predicted that a particular form of “thundyer” of silicon dioxide, described in the 1960s as typical of meteorites, would exhibit the distinctive characteristics of a hybrid crystalline glass material with a thermal conductivity that remains unchanged with the temperature. This unusual thermal transport behavior has analogies with the invarity effect on thermal expansion, for which the Nobel Prize in Physics was awarded in 1920.
That led the team to the experimental groups of Etienne Balan, Daniele Fournier and Massimiliano Marangolo in France, who obtained a special permission from the National Museum of Natural History in Paris to perform experiments on a sample of carved silica tridimite of a meteorite of a meteorite in the meteorite of a meteorite that landed in Germany, in 1724. His experiments confirmed his experiments. Meteoric Treatorit falls between an orderly glass and messy glass, and its thermal conductivity remains essentially constant on the experimentally accessible temperature range from 80 k to 380 k.
After additional investigation, the team also predicted that this material could be formed from the thermal aging of a decade in refractory bricks used in furnaces for steel production. Steel is one of the most essential materials in modern society, but producing it is carbon intensive: only 1 kg of steel emits approximately 1.3 kg of carbon dioxide, with the almost one billion tons produced every year that represents approximately 7% of carbon emissions in the materials of the United States derived from tridymite could be used to more efficiently control the intense heat that involves the production of steel in the production of steel in the production of steel Steel, helps reduce the steel steel industry.
Future: From the solutions of the theories of the first principles to the technologies of the real world
In this new PNAS article, Simoncelli used automatic learning methods to overcome computational bottlenecks of the traditional methods of the first principles and simulate the atomic properties that influence heat transport with quantum level precision. Quantum mechanisms that govern heat flow through hybrid glass materials can also help us understand the behavior of other excitations in solids, such as electrons that transport load and magnons that transport rotation. Research on these issues is to shape emerging technologies, including portable devices fed by thermoelectric, neuromorphic computing and espintronic devices that exploit magnetic excitations for information processing.
The Simoncelli group in Columbia is exploring these issues, structured around three central pillars: the formulation of theories of the first principles to predict experimental observables, the development of the simulation methods of AI for quantitatively precise predictions of the materials of the materials and the application of theory and methods to design and discover materials to overcome the specific industrial or engineering challenges.
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