Bizarre new material discovered in Hiroshima bombing debris

The detonation of an atomic bomb creates a distinct chemical environment that is nearly impossible to replicate in a laboratory. Amidst its destruction, such an explosion can produce entirely new materials.

The atomic bombing of Hiroshima in 1945, one of the most catastrophic explosions on Earth, resulted in the formation of a metallic material previously unseen in both laboratory and natural settings. Luca Bindi, an earth scientist from the University of Florence in Italy, discovered this alloy while gathering microscopic debris along the beaches of Hiroshima Bay. He remarked that even after decades, a grain just a few micrometers in size can preserve a detailed record of the conditions that existed for mere fractions of a second. “These particles are not simply melted debris. They are physical archives of the explosion,” he explained.

A nuclear explosion impacts its environment similarly to lightning or a meteor strike. The air heats to extreme temperatures and rapidly cools, causing different materials to vaporize and combine in unusual ways. This rapid process prevents vaporized metals from stabilizing as they typically would, turning “every small droplet effectively [into] an independent experiment,” according to Bindi.

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In this instance, one of the countless “microexperiments” during the Hiroshima explosion resulted in an alloy primarily composed of iron, chromium, nickel, manganese, molybdenum, silicon, and aluminum, arranged in a homogeneous cubic lattice. The composition and structure of this material are unprecedented—normally, such a blend of elements would form a simpler crystal structure with fewer components, but here it maintains a complex cubic design.

In the past, scientists have discovered new substances formed under nuclear or other extreme conditions. One example is trinitite, a glassy material from the Trinity nuclear bomb test in July 1945. Trinitite features a novel, cagelike clathrate crystal and quasicrystals, rare materials with nonrepeating atomic structures, previously considered impossible. Quasicrystals have also been found in meteorites. Although the alloy discovered in Hiroshima Bay is not a quasicrystal, its structure offers insights into understanding them better, according to Bindi, due to its similarity to atomic arrangements found in quasiperiodic materials.

Published in Science Advances, this discovery raises questions about the kinds of substances extreme events can create and whether they are isolated occurrences or part of a broader class of materials, Bindi notes. He suggests that if this broader pattern holds true, atomic-blast debris might help uncover principles of matter formation applicable to meteorite impacts, lightning strikes, and other violent natural events.

The finding highlights “a whole world largely untouched” of materials difficult to create under stable conditions and hard to find in ordinary locations, says Michael Widom, a physicist at Carnegie Mellon University who has collaborated with Bindi before. “[Bindi] rightly recognizes that if you want to find new materials, they’re going to be in unusual places.”

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