064206Structural, magnetic and electronic state characterization of L10-type ordered FeNi alloy extracted from a natural meteorite

To understand the hard magnetism of L1(0)-type ordered FeNi alloy, we extracted the L1(0)-FeNi phase from a natural meteorite, and evaluated its fundamental solid-state properties: sample composition, magnetic hysteresis, crystal structure and electronic structure. We executed multidirectional analyses using scanning electron microscopy with an electron probe micro-analyzer (SEM-EPMA), a superconducting quantum interference device (SQUID), x-ray diffraction (XRD) and magnetic circular dichroism (MCD). As a result, we found that the composition was Fe: 50 : 47 +/- 1 : 98 at.%, Ni: 49 : 60 +/- 1 : 49 at.%, and an obvious superlattice peak is confirmed. The estimated degree of order was 0.608, with lattice constants a = b = 3 : 582 angstrom and c = 3 : 607 angstrom. The obtained coercivity was more than 500 Oe. MCD analysis using the K absorption edge suggests that the magnetic anisotropy could originate from the orbital magnetic moment of 3d electrons in Fe; this result is consistent with that in a previous report obtained with synthetic L1(0)-FeNi.