Brief
Chinese team finds rare cubic iron in Chang‑e 6 lunar glass
The discovery suggests impact‑formed glass may preserve magnetic information about the Moon’s early magnetism.
By Felo News Desk · Published
Researchers led by Prof. Haifeng Du at the High Magnetic Field Laboratory, Hefei Institutes of Physical Science, reported that metallic iron in impact glass collected by China’s Chang‑e 6 mission includes face‑centered cubic γ‑Fe, a form previously unseen in natural lunar material. The study, published in the Proceedings of the National Academy of Sciences on September 16, used focused ion‑beam preparation, transmission electron microscopy and off‑axis electron holography to examine two glass samples.
γ‑Fe dominated the iron particles and remained stable despite cooling, which normally converts it to α‑Fe. The team proposes that rapid cooling, carbon impurities and encapsulation within the glass matrix allowed the high‑temperature phase to persist. Magnetic testing showed that larger γ‑Fe particles formed a single‑vortex state and retained a consistent response to external fields, indicating they could act as tiny magnetic fossils.
"This tiny magnetic fossil may help us better understand the Moon's ancient magnetic history," said Dr. Long Li of HFIPS, a member of the research team.
Key facts
- Face‑centered cubic γ‑Fe was identified for the first time in natural lunar samples. (sciencedaily.com)
- The discovery was made in impact glass collected by the Chang‑e 6 mission. (sciencedaily.com)
- γ‑Fe particles remained magnetic and formed a stable single‑vortex state. (sciencedaily.com)
- Researchers used focused ion beam, TEM and electron holography to analyze the samples. (sciencedaily.com)
- Study led by Prof. Haifeng Du and published in PNAS on September 16. (sciencedaily.com)
Sources
- [1] sciencedaily.com — originally reported as “Chang’e-6 lunar soil contains a surprising magnetic time capsule”
