2002/12/13 by R. J. Harrison, Rafal E. Dunin‐Borkowski, Andrew Putnis · 1 citation
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · Energy · #Geomagnetism and Paleomagnetism Studies #Geophysical and Geoelectrical Methods #Iron oxide chemistry and applications #Magnetite #Magnetic domain #Spinel #Electron holography #Magnetization #Transmission electron microscopy #Nanoscopic scale #Magnetic force microscope #Condensed matter physics #Microstructure #Materials science #Demagnetizing field #Vortex #Optics #Magnetic field #Nanotechnology #Physics
paper · doi:10.1073/pnas.262514499
openalex publication_date 2002/12/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26
The magnetic microstructure of a natural, finely exsolved intergrowth of submicron magnetite blocks in an ulvöspinel matrix is characterized by using off-axis electron holography in the transmission electron microscope. Single-domain and vortex states in individual blocks, as well as magnetostatic interaction fields between them, are imaged at a spatial resolution approaching the nanometer scale. The images reveal an extremely complicated magnetic structure dominated by the shapes of the blocks and magnetostatic interactions. Magnetic superstates, in which clusters of magnetite blocks act collectively to form vortex and multidomain states that have zero net magnetization, are observed directly.