Magnetic Mineral Remembers

Greigite, one of nature's strongest magnetism carriers, forms almost exclusively as polycrystalline flakes, and because of its elaborate microstructure, the analysis of its magnetic state has been challenging. In a new article, an international team from Switzerland, Germany, Tennessee, and UL Lafayette (Dr. Michalis Charilaou), used synthetic greigite flakes, and performed magnetometry and ferromagnetic resonance experiments in concert with micromagnetic simulations to assess the magnetic state in these flakes. The team found that the intricate microstructure in greigite flakes generates a form of magnetic memory effect, where different field strengths can be used to manipulate its magnetic configuration. This finding highlights novel traits with which to detect natural greigite and to assess its fidelity as a paleomagnetic information carrier. The research was published here.  This brings us closer to understanding one of Earth's more important magnetism carriers that has recorded its history for millions of years.