Wikipedia (It is a metal in the first transition series. It by mass is the most common element on Earth, forming much of Earth's outer and inner core)
Electronic configuration: Fe 1s2 2s2 2p6 3s2 3p6 3d6 4s2 with a net moment of 4 BM of 4 unpaired d electrons, Fe2+ is Fe minus 4s2 again with 4 unpaired d electrons, Fe3+ 1s2 2s2 2p6 3s2 3p6 3d5
6 4s2 with 5 BM.
Magnetism: metal is ferroomagnet at rooom temperature
Link to Iron Oxides
Low spin - intermediate spin - high spin Fe(III) (Figure 2)
- alpha Fe2O3
= hematite, the most stable Fe2O3, our measurements (IMFM, Ljubljana, 2014) on bulk sample (Morin transition at 250 K):
MH and zfcfc.
With decreasing the particles' size, Morin transition shifts to lower temperatures. (O. Ozdemir, D. J. Dunlop, T. S. Berquo, G3 9, 2008)
Hematite nanoparticles Inset in Fig. 9 is for M(H) bulk hematite.
Synthesis and magnetic properties of concentrated alpha-Fe2O3 nanoparticles in a silica matrix.
= magnetite, Magnetite is a mineral and one of the main iron ores. With the chemical formula Fe3O4, it is one of the oxides of iron. Magnetite is ferrimagnetic (wiki).
At low temperatures, magnetite undergoes a crystal structure phase transition from a monoclinic structure to a cubic structure known as the Verwey transition. The Verwey transition occurs around 121 K and is dependent on grain size, domain state, and the iron-oxygen stoichiometry. An isotropic point also occurs near the Verwey transition around 130 K, at which point the sign of the magnetocrystalline anisotropy constant changes from positive to negative. The Curie temperature of magnetite is 858 K (585 deg C). (wiki)
zfc and fc, Verwey transition.
Fe3O4 nanoparticles, superspin.
In 1968, Kai et al. found that ZrFe2 is a typical ferromagnet, with a Curie temperature of 630 K and a magnetization of 88 emu/g. PHYSICAL REVIEW B VOLUME 27, NUMBER 11 1 JUNE 1983, Electronic structure, superconductivity, and magnetism in the C 15 compounds ZrV2, ZrFe2, and ZrCo2, B.M. Klein, W. E. Pickett, D. A. Papaconstantopoulos, and L. L. Boyer