Scientists Identify New Metal Alloy from 1945 Hiroshima Atomic Bomb

Scientists from the University of Florence led by Prof. Luca Bindi have identified a previously unknown multicomponent metal alloy in microscopic fallout particles collected from the sands of Hiroshima Bay. The particles, termed “hiroshimaite” or “hiroshimaites,” were formed in the nuclear fireball of the August 6 1945 atomic bomb “Little Boy,” where temperatures exceeded 7,000 °C, vaporising buildings, steel, glass and soil. Rapid cooling trapped the atoms in a unique crystal structure.

Chemical analysis shows the alloy contains iron, chromium, nickel, manganese, molybdenum, silicon and aluminium – elements that originated from the city’s infrastructure. The discovery, published in Science Advances in 2026, provides new insight into matter behavior under extreme conditions and could inform the design of novel heat‑resistant alloys. The finding also adds a rare physical record of the seconds after the world’s first nuclear explosion.