Phase transformation and exchange bias effects in mechanically alloyed Fe/magnetite powders

Modified nano-magnetite coated carbon fibers magnetic and microwave properties

“…5 (c)), which may be due to the exchange bias effect. Although, this phenomenon usually exist in systems which contain exchange interaction between the antiferromagnetic and ferromagnetic phases at their interface [34], it can occur in systems containing ferrimagnetic phases and disordered phases with spin-glass behavior [35,36]. As formerly mentioned, Fe and magnetite phase coexist in the MCCFs-60 sample.…”

“…Considering the results, it can be derived that the increasing weight fraction of the MCCFs in absorbent composite materials tends to converge and create a valley in the frequency range of 9-9.5 GHz. For the low content of MCCFs, the weakening of incident microwaves was dominant to absorption (in the other words, reflection is relatively low), while at high concentrations of MCCFs, reflecting prevails the weakening [36].…”

Synthesis, morphology, microstructure and magnetic properties of hematite submicron particles

“…During the last decade iron (III) oxides have been at the focus of a remarkable research interest due to a wide variety of properties, as well as possessing a huge potential for applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Among seven polymorphs of iron (III) oxide, ␣-Fe 2 O 3 (hematite) in various forms (such as bare nanoparticles, nanowires, microcubes, rods, microspheres, nanorods, nanotubes, and nanoparticles embedded in an inert matrix) has been under extensive investigation in order to understand the influence of size, shape, anisotropy, microstructure, inter-particle interaction and surface effects on its physical properties.…”

Fe and Co methylene diphosphonates as conversion materials for Li-ion batteries

“…The resulting χ(k) functions were weighted with k 2 to compensate for the dampening of the XAFS amplitude with increasing k. The resulting k 2 -weighted spectra were Fouriertransformed in a window of 3-11 Å -1 . The fully reduced sample was fitted in the Fourier transformed EXAFS in the range of 1.4-2.9 Å using the first Fe-Fe scattering path from a Feff calculation based on the α-Fe crystal structure (ICSD #180971, [18]). The fully oxidized sample was fitted in a window of 1-2.9 Å in the Fourier-transformed spectra using three scattering paths (Fe-O, Fe-P and Fe-Fe based on reasonable average values of the corresponding paths calculated from the crystal structure of pristine lithium iron methylenediphosphonate [11]), where all parameters were allowed to run free, as due to the amorphisation it was not clear if the interatomic distances of FeMeDP would be preserved.…”