Extreme-event materials, Pg2

Key Highlights:

• Researchers discovered a previously unknown metal alloy formed by the 1945 Hiroshima atomic bomb blast.
• The alloy was found embedded in small, glass-like beads called hiroshimaites, recovered from the beach sands of Hiroshima Bay.
• The discovery was published in Science Advances on July 29.
• The alloy formed due to the extreme heat (over 7,000 degrees Celsius) and subsequent ultrafast cooling of urban materials.

Detailed Insights:

• The hiroshimaites are glass-like beads that formed when intense heat vaporized building materials, soil, and metals, which then solidified upon falling.
• The micrometer-sized metallic grain identified within the beads is a complex mix of iron, chromium, nickel, manganese, molybdenum, silicon, and aluminium.
• The unique crystal structure of the alloy is attributed to ultrafast quenching, a process where elements mixed under conditions impossible to replicate normally.
• This discovery suggests that high-energy plasma events, like nuclear detonations, can act as natural laboratories for discovering new materials.
• The alloy shares characteristics with other unusual high-entropy alloys and quasicrystals.
• The research highlights how debris can preserve a "high-resolution record" of the chemical and physical environment during a nuclear event.

Scientific/Technical Concepts Involved:

• Hiroshimaites: Small, glass-like beads formed from vaporized materials during the Hiroshima atomic bomb blast.
• Ultrafast quenching: A rapid cooling process that can lead to the formation of unique material structures.
• High-entropy alloys: Alloys containing multiple elements in near-equimolar ratios, often exhibiting unique properties.
• Quasicrystals: Materials with an ordered, but non-periodic, atomic structure, unlike traditional crystals.