https://phys.org/news/2021-10-3d-imagin ... phous.html
by California NanoSystems Institute
Many substances around us, from table salt and sugar to most metals, are arranged into crystals. Because their molecules are laid out in an orderly, repetitive pattern, much is understood about their structure.
However, a far greater number of substances—including rubber, glass and most liquids—lack that fundamental order throughout, making it difficult to determine their molecular structure. To date, understanding of these amorphous substances has been based almost entirely on theoretical models and indirect experiments.
A UCLA-led research team is changing that. Using a method they developed to map atomic structure in three dimensions, the scientists have directly observed how atoms are packed in samples of amorphous materials. The findings, published today in Nature Materials, may force a rewrite of the conventional model and inform the design of future materials and devices using these substances.
"We believe this study is going to have a very important impact on the future understanding of amorphous solids and liquids—which are among the most abundant substances on Earth," said the study's senior author, Jianwei "John" Miao, a UCLA professor of physics and astronomy and a member of the California NanoSystems Institute at UCLA. "Understanding the fundamental structures may lead to dramatic advances in technology."