Local Electronic and Crystal Structure of Rare-Earth Cobalt Phosphides RCo2P2 Studied by XAFS Spectroscopy

The valence state of Ce and Eu was investigated by X-ray absorption near-edge structure (XANES) spectroscopy above L3-Ce and L3-Eu absorption edges in series of RCo2P2 (R = La, Ce, Pr, Eu) magnetic intermetallics. At the same time under similar conditions the rearrangement of Co and Pr local environment vs. temperature was studied by extended X-ray absorption ¯ne structure (EXAFS) spectroscopy above K-Co and L3-Pr absorption edges.

Mössbauer Spectroscopic Analysis of Nd2Fe14B/α-Fe Hard Magnetic Nanocomposites

Among novel magnetic intermetallics based on rare earth-transition compounds, the Nd2Fe14B/α-Fe isotropic nanocomposites have been obtained by recrystallization from an amorphous phase, prepared by melt spinning. For variable 5 wt.% Fe and 10 wt.% Fe contents we recorded transmission 57Fe Mössbauer spectra at the room temperature, hardened of the α-Fe phase by exchange interactions. The spectra have been analyzed in terms of ten Zeeman sextets and one paramagnetic doublet related to the Nd1.1Fe4B4 phase. One sextet corresponds to the α-Fe phase, whereas others are attributed to six non-equivalent Fe sites in the Nd2Fe14B structure, namely 16k1, 16k2, 8j1, 8j2, 4c, and 4e. The three remaining sextets belong to the Fe3B structure with three inequivalent Fe sites FeI(8g), FeII(8g) and FeIII(8g). All relevant parameters for both nanocomposites: the magnetic hyperfine field, the isomer shift and the quadrupole splitting are determined for each of these sites.